If you use YouTube through Safari, it has extensions that can help. I’m using AdGuard (paid, but I’m not sure that’s necessary), Vinegar, and SponsorBlock and I never see ads on Youtube. Pretty sure the reason is AdGuard, though.
If you already submitted the command, you’ll have to hit Up first to have a line to jump to the beginning of, though, so it’ll be the same number of keystrokes either way.
I do the same thing you do, just with vi-mode keystrokes (up, then esc-I).
Yeah - the tweaks can be substantial and they have the flexibility to do more. Brave has a whole development pipeline for incoming Chromium changes so they can intentionally bring in code they want and avoid bringing in code they don’t want, like FLoC, or changes that would conflict with their own tweaks. But I don’t think many other browsers change a ton in the engine itself, so you effectively end up with them getting as much customization of Chrome, Firefox, or maybe of Safari (mostly of Chrome) as Apple allows browsers on its platform.
Having older versions isn’t generally an advantage, unless you’re trying to test for compatibility or something similar. It means you’re more vulnerable to known threats that have been patched in current versions of browsers