There were some projects when I was running on a G3 iMac where I would drop the render screen down really small to see how it would perform on a more powerful machine. It felt like if they even managed to get decent GPU acceleration possible then they could have solved a lot of these issues.
Unity kind of took its place in the game space.
Web pages - nothing. They're all using some boring non visual JS library.
The technical legacy of Flash made it a poor fit for touch screens. Apps filled that void with astounding speed.
This part is just a vague opinion I am riffing with - With mass available video, a ocean of video content may have changed tastes enough that the demand for interactive content diminished somewhat. Social media also killed of the dedicated website for a lot of places that used this technology and thus the demand for this stuff.
Once Google via Chrome closed the Flash hole, I do wonder if they will ever let anyone else to try and get in on that space? Time will tell.
Relative to what though? There was nothing else with its ubiquity, ease of use and deployment, and breadth of functionality.
It pioneered and enabled so many things that we take for granted on the web today.
Personally, as someone who used it extensively, I don't feel it was particularly buggy, especially relative to the alternatives or developing in the browser. It could have performance issues, if developers did bad things or pushed it too hard, but you could say that for just about anything.
As far as security, it was the single most ubiquitous runtime on the web, and thus was a prime target for hackers. Yes, it had security issues (although every web runtime did), but its not like the rest of the web / browsers were particularly secure themselves.
fyi, I worked for Macromedia and work for Adobe now, but these are my personal opinions.
Maybe I am just remembering it differently as this was more than a decade ago. But it seemed like almost every week, heck almost every day, another zero day would be discovered. Yes, this was the peak time of zero day exploits as every system was being hammered from all sides, but the Flash name came up far more often than anything else I recall expect for maybe general Windows Xp/7 issues.
As for performance, that was a major issue personally. I recall a time when I had nested items a few layers deep so that I could have a character with movable joints and the system was buckling under this work load. Going from fully ridged models running smooth as butter on 3DS Max to the same system crumbling under some basic vector graphics left a bad taste for me. It just always felt like it was dragging its feet compared with what these machine could achieve.
I don't recall any specific bugs only that recall the feeling of them. Sorry I am so light on specifics. A minor bug was that I do recall was as you rotated objects, there must have been a small rounding issue that meant items would slowly shrink as you rotated them multiple times while going about your process. It would take hundreds of such movements before it became noticeable, it was a funny little thing but would lead to some projects becoming a bit frustrating.
I say this as someone who absolutely loved Flash. I wish it had kept on going regardless of those issues. It just felt like it needed a Windows Vista to Windows 7 moment. Where it was taken to task and team got behind it to refine the project into something much more lean that still had the same functionality. Instead it felt like it was treated as that thing that would get barely any attention until it died from atrophy. That mobile wasn't taken to task is probably the thing that ended up killing it quick.
As someone else said here, Flash felt like a vision of the future. Where computers were tools of creation made easy not just consumption.
It was a pioneer in so many things and I wish it was still a part of the web. It made interactive media distribution so dang easy! Build it in Flash, add a single line of HTML and BOOM - multi-platform audio visual experience that could scale like a champ!
Yeah video kind of sucked, early Youtube performance a good example in that as it would bring my G4 Mini to it's knees! But for everything else it was such a visionary idea that we have lost.
On a tangent.
This is something that I feel a lot of modern technology has forgotten. That vision of not just new tech but tech that is enabling to even those that have no interest on the base technology. Flash had that vision, not just of creation but the ease in which it could be spread. Hypercard had that vision. Heck BASIC had that vision. As Steve Jobs always pushed in the early 80's, the computer is a cycle for the mind. Nowadays at times it can feel like the sedation of the mind.
Everytime I see here on HN another link about thing Ruby, GCC, CLANG, some JS framework, Tensor... something - I get it, in those fields it is all very cool and useful. But it is also very much for those that work in the weeds. Great for those that do that, but it also feels so lacking of that "Wow!" factor that I think brought a lot of us into this field. I hope we rediscover that one day and soon.
One of the tradeoffs of the time was that they had to work very hard to both crunch the binary size down for Flash itself, as well as Flash files, because people everywhere were extremely bandwidth-limited - when dialup was the most common method for connecting to the internet and not even 56k was necessarily ubiquitous at that. And of course, compiler technology hadn't come as far as it has nowadays.
The weight of all the decisions that made Flash able to succeed eventually worked against it, but for its time, it was an extremely good implementation that made the web as a whole more interactive.
I'm happy it's been superseded, but I think that it was the right product for its time.
But the idea of having a single file that could bundle, code, audio, graphics that was dead easy to build and could run independent of specific browsers and operating systems.
That is something magical. It is harder to build that kind of content today and near impossible to implement it on that scale today than it was 20 years ago.
Theoretically you could run a Flash file on a Linux system via Konqueror browser and it would be identical to that on Internet Explorer on Windows 98. This is something we have lost.
It is a shame that Adobe/Macromedia treated it like absolute trash. A free/open solution that had the same good properties would have been brilliant but it never happened. Instead we have the whole HTML5+ stack. I mean it is cool and has done some amazing things for the web, but it is also a massive pain to manage. One browser update and boom, something has broken - time to get digging on what happened! Now it works on Chrome but not Firefox!? Oh dear.
I don't miss Flash itself, I mean to be charitable, it was a mediocre product at best. But that vision implemented in a sensible fashion could have been wonderful. Could have allowed for the decentralized web to continue on a bit longer than it has.