You'll have no choice and your love will be mandatory.
This won't stop malware of course. However a skull clamp will be installed to monitor your thoughts and you will be zapped if undesirable thoughts are detected.
Note: it's a hyperbole but if you want another OS, Browser or hardware you'll be forced to Homebrew it. Or use a compromised app.
As for other browsers: I guess that you'd still be able to access my website, but YouTube and GMail will just show you a generic "This browser is not supported" or, at best, "Your browser had been deemed insecure. Please use a secure browser".
If we go full Nostradamus the most likely result is that Safari will play ball (because they are already doing something similar), Firefox will play ball (because they no longer have a spine), they'll implement whatever Google says, and yet another portion of the web will be closed to those who don't dance to Google's tune. I hope you're not too attached to youtube-dl or your adblocker.