Just a very brief synopsis...

I see little difference between what they do and what FBook and Twitter and the rest of Big Tech do. They collate data about their members and sell the information to other corps and to govts (especially to China...though it is not obvious why China wants the info at this time).

All browsers realised they had to provide security so that google and others cannot spy on us...and then Brave comes out with a browser created to help everyone spy on you, but offer to pay you for allowing it. For you to see the adverts, it means you are open to being spied upon. Apart from your browing habits being recorded, each time you click on an advert, you are creating an image for an AI system to create an image that describes how you think and feel...so that govts and large corps can manipulate you more effectively.

There is a lot of information on the web about this subject, I am surprised you have not read any of it.

A different example, which may be easier for you to understand as I see your post often about crypto currencies. Why do you think govts want to force the various currencies to disclose all coin holdings and earnings? By us removing ourselves to an independent currency, they are losing control over us.