I don't think memory was the main issue. It sounds like there was some software installed that was using up the CPU -- some background utility run amok.

I've got an 8 GB M1 MBA and run Chrome and an IDE effortlessly, even when connected to a 4K monitor, and with tons of tabs open.

I'm not saying 8 GB is enough for everybody, but it's perfectly fine for an IDE and web browser. I'm pretty sure your issue was something else.