Auto-play videos suck. They use bandwidth, and their annoying sounds get in the way when you’re listening to music and open a web page. I happen to write for a website that uses them, and it annoys me to no end. (My editors have no control over those auto-play videos, alas.)
But you can stop auto-play videos from playing on a Mac. If you use Chrome or Firefox, it’s pretty simple, and the plugins below work both on macOS and Windows; if you use Safari, it’s a bit more complex, but it’s not that hard.
The most egregious user of autoplay videos in the Mac community must be Macworld. The site has been taken over by marketing weasels and is a shadow of its (useful) former self.