That said, its a standards body. If you arent standardizing what the majority of the marketshare web browser vendors want, you're not creating standards, just pipe dreams. Consensus is what a standard is. It is not the same thing as regulation.
Google profits from this in two ways. Because they own the largest browser by market share, the ... is usually that, making other browsers less viable. But in addition to that, this significantly raised the barrier to entry for any competing browsers - remember what happened to Edge?
Was it though? At a minimum i think a "standard" is a document detailing the behaviour of at least two competiting implementations sufficiently that you could use it to make a new implementation that was interopable. I don't think that was true of W3C standards in the pre WHATWG days. Compare it to say the HTTP rfcs, which i think did meet that standard.
It has to, because such implementations would be extensions that standard compliant code can't rely on.
It was a fairly brief period, unfortunately - roughly between IE losing definitive market dominance, and Chrome acquiring the same.