Sadly, uMatrix is no longer developed. It's like NoScript before NoScript existed - and if NoScript was on steroids.
PaleMoon users:
addons.palemoon.org
Note the warning. It WILL break sites. It's basically like a detailed old-school firewall, except it's for your browser. You WILL block things that stop sites from working. Once you see how much cruft you're blocking, if you haven't seen it before, you'll likely be a bit surprised.
What you do is you set it up for the sites you regularly view and let it block everything on other sites. When you visit a new site, you go through and allow what's needed to at least view the content and leave it there. It does take time and effort and it is not recommended for new people who aren't technically minded.
(Do not install this on grandma's computer, unless she's savvy with this sort of stuff.)
It doesn't just block scripts. It'll block anything you might think of, from CSS to third party CSS, from images to third party images, from scripts to third party scripts, etc...
If you want, you can still use uMatrix. Even though the author (same dude, Raymond, that does uBlock Origin) no longer develops it, there was a vulnerability found and he fixed that a few years ago. It's still available to download and install if anyone wants to play with it.
I can't find a properly maintained fork for other browsers. Though, it is feature-complete and stable.