I also run a very low end machine with 4GB ram. The issue often isn’t the browser or even the website, exactly, it’s the tons and tons of advertising and tracking crap that is in the background of most sites nowadays. Tue way around that is to run a solid ad blocker. uBlock Orgin is the best, but Google (and maybe MS? I don’t use windows) has fucked over plugins to specifically make things like it not work. So, what you want to do is run Firefox with uBlock Origin with the more aggressive blocking setting. Extra credit for setting up PiHole to block a different set of crap.

The one thing is that this will absolutely break certain sites. But fuck those sites, they’re fucking you.