I have a 2015 MBP as well... it's HORRIBLE when I hook it up to a 4k monitor. Lag, freezing, etc. I can still get stuff done, but the experience is pretty bad.

Perfectly fine on its own screen though, the dual-core in mine just isn't up to the task of a 4k external monitor.

Your web browser probably doesn't have many tabs open, and those that are open, are probably not web apps (think Slack, Facebook, WhatsApp, various internal corporate apps, etc.).

I can't even remember a time when just my web browser used up less than 4-5 GB of RAM, on its own.

Add at least 500MB - 1 GB for the OS itself, and we're talking about 2 - 3.5GB for apps. I'd immediately swap with just 8GB of RAM with an IDE and a DB running.

I have four browser windows filled crazy number of tabs on M1. I’m yet to experience any slowdowns.

You’re right, I can’t mentally deal with more a few open tabs and I use none of those webapps at home. I might be an outline in the other direction, but there’s a lot of room between using maybe 4GB of RAM in total an using that for a browser alone.

Auto-tab-discard on Firefox is your friend. Makes thousands of tabs possible with almost no memory use and seamless functionality.

I do visit 20-40 of those tabs regularly. They're SPAs so they use up a lot of memory.

How often? I set mine to discard after 60 minutes, except for slack, WhatsApp and a couple of others; cost is reload when I do venture into discarded tabs - e.g. I scan HN and Reddit headlines in the morning, open each interesting comments page in a tab; much later, when I have downtime, I visit them - but I used to reload to get the new comments. Now with ATD, they get reloaded automatically, so for that use it is even bette than the real thing.

What IDE are you using?

None, I use Vim or TextMate. But you have a point Xcode isn’t fast on my laptop. You use it, but if I where to use Xcode professionally I’d get a newer machine with more memory.

I have been working on a TVOS app, and it works fine, but there is some waiting involved.