I think it's the latter. I don't think Google really cares about the default search engine. Microsoft didn't take the money and have their own stuff but it does

I think it's the latter. I don't think Google really cares about the default search engine. Microsoft didn't take the money and have their own stuff but it doesn't make any dent in Google's popularity (even now that Google is terribly enshittified and pretty much everything else is now better) I think it's propping up the competition to be just enough to be considered competition, but not really interfere with them milking their internet domination.