Potentially. However, anecdotally a lot of service providers treat UDP to stricter rate limiting than TCP because it’s unauthenticated nature, so there is a back-pressure factor there.

Also: RFC9000 for QUIC is almost 50% longer than RFC9293 that is the new one for TCP - so, I would expect the implementation would be probably more complex ?

In the absence of that, everything will go over HTTP :-)