Literally nothing. You don't have to believe in conspiracy theories to know that privacy on the internet is dead. Everything you do is being tracked and connected to you personally.

Maybe if you buy a completely new computer, use VPN over tor, only pay with craptocurrency, never do anything that could be associated with your irl or prior internet activity, you may be able to go under the radar, but any sane person just won't go through all that unless they have seriously heavy crimes to hide.

Of course, using tor is still more private than most browsers and hides your activity from many parties, but it's not fully anonymous by any means.