Look, I’m not attacking them over this, as you rightly said, it has plenty of other drawbacks and concerns, I’m just emphasising that Google do have a large degree of influence over them. For instance, Chromium is dropping manifest v2 support, so Brave pretty much has to do the same. They’ve said that, as Chromium has a switch to keep it enabled until June (iirc) they’ve enabled that, but after Chromium drops manifest v2 the most they can do is try to support a subset of it as best they can. The Brave devs may not want to drop support, but Google have decreed it will be dropped, so they end up dropping it and having to put in extra work to keep even a subset working for some period of time.

If Brave gets even a moderate market share, Google will continue to mess them around like this as they really don’t like people not seeing their adverts.

Ultimately it’s software, so the Brave devs can do pretty much whatever they want, limited by the available time and money. Google’s influence extends to making that either easier or harder, it much the same way as they influence the Android ecosystem.