Perhaps I could rephrase that to “could opt to unimplement”. These people are smart enough to check and verify the changes in the browsers that they ship.
These alternative browsers are essentially also forks of chromium. They pull in changes from upstream. I’m not well versed in browser engine development or how these teams keep their engines up to date, but I’m sure there’s a person or team responsible for checking and pulling the changes. They could decide to not pull that in, if that code is properly boxed and not all over the place, but still the commits to that feature will show what and where. They still have that choice to stray from upstream, but it might be hard to maintain in the long run if the code is all over the place.
It sounds that it actually is safer, that people for example can expect there are no malicious mitm things spying on their browsing or changing/injecting things that are malicious (like these scams lately where they ask to take over your computer and change numbers via dev tools because people don’t know what the fuck they’re looking at), but at the same time it would make things very cookie cutter. Ads everywhere, no way of changing things with client-side scripts, no looking at source code because why would you can’t change it anyway, no alternative frontends for popular websites with horrendous tracking, etc.
Of course, that is for the websites that take advantage of this technology. I can’t predict how many websites would implement this, but I hope deep down there are still websites that would not go this route and remain free to visit and browse. That will be my world wide web. I know where the web came from, taking a step back to a smaller sub-web of sorts doesn’t really scare me, it might even bring back some of that forgotten glory of what the web once was. Smaller, less content, but with heart.
I would happily find/join a corner of the web that’s more reminiscent of the older world wide web, where shit like this doesn’t fly. Just people sharing knowledge and discussions and self made pages on random topics. Completely free from corporate influence. I get that servers aren’t free, but with the speed of domestic internet and the power of current hardware I don’t think it’s impossible to set it up cheaply and not have to rely on ads to keep running.
You can also check out Wargus for older Warcraft games