As for whether its beneficial to society is another question.
It's not exactly a success (except from the most selfish and financial perspectives), it's more like proof you can abuse your users and get away with it.
I used facebook messenger to keep in touch with my family across the world. My family is incapable of using signal, whatsapp, sms, email, telegram, phone calls, or anything else.
I also use facebook to buy stuff on the classifieds. It's like craigslist except there's at least a picture of someone and a paper trail if they decide to murder me.
My neighborhood organizes events using a facebook group and we've been able to have festivals and organize groups to go fight against companies that want to industrialize the area.
Facebook is trash at what it was initially built to be, but it is still very useful.
What about Myspace? $800m in revenue from 115m users. The classic 'good product' story, right?
Facebook makes its money by leaving the feed an unorganized mess of random posts, leaving the user disoriented so that more eyeball time can be harvested for advertisements while the user searches for the content they want (or gets stuck mindlessly scrolling the infinite reel of videos and other content for that dopamine hit).
It's not lost on the army of six figure salaried engineers that a lot could be done easily to make the experience better. But that isn't in the interest of the shareholders. The quality is a feature, not a bug.
In fact, it's sometimes unusable on Firefox on an M1 MacBook Air.
For one thing, the "report a bug" tool doesn't work in my browser but it works perfectly fine in Chrome. I can't click the dropdown boxes— they're empty. I also can't submit my report in the rare instance the drop downs work.
I also get weird trouble where my news feed will just start randomly loading crap and go into a rapid endless scroll loading new stories. The only way I can stop it is to do a hard refresh.
There are so many problems with posts not updating... You get a notification about some new comment like and when you click the notification, it just shows how it looked the last time you loaded it.
Again, the only way to see the update is CMD + R.
It's so broken and the latest interface doesn't even feel good, new, fresh, or like you want to explore.
This is basically the same philosophy as "Worse is Better" (in contrast to "Do the Right Thing") and it's how UNIX and C took over "like a computer virus".
I'd say Facebook has succeeded in that "viral" aspect, unfortunately for society. Apparently, their broken interface is good enough for a lot of people.
Their software development philosophy is not the reason why Facebook is falling apart. It's their lack of vision, lack of respect, decency, human values, care and social responsibility.
They could even extend their biometric capabilities could even step into the ‘slightly unethical’ realm, by perhaps detecting a flirtatious message from a profile with a cute Japanese girl, via somewhere in Northern Africa. Even just putting basic controls around messages from complete strangers.
So how did the break-things experiment go? Is it a success because the stock was at one point worth an inconceivable amount of money? Or is it a failure because it can't stand up under its own weight and will never catch up to its inevitable successor?