The idea for most people using Brave Browser (which blocks adverts, trackers, etc) is to use the auto-contribute option to spend some money with sites you often use and which do not show intrusive adverts, or fee sites without adverts.
Everything costs money to operate on the Internet and normally the site owners don't charge users anything, but they are recouping profits from advertising or selling behavioural data, and then turning a good profit (a bit like Google and Facebook). When did Google or Facebook last pay you out for what they earn from you?
I've turned off my general auto-contribute and keep it on for the sites I use a lot (Minds, Pixelfed, Lbry, etc), giving them a larger share of what I contribute. My own website is advert and external tracker free, and I became a certified Brave creator too, so I can also receive contributions from anyone visiting my site (it's their choice to activate or not).
It may not be perfect but it is an interesting alternative model and does mean sites supporting it are not crammed full of adverts and trackers. A nice feature is being able to deactivate the cross-site single sign-ons for Google, Facebook, LinkedIn.