Even in the EU, couldn't there still be a privacy benefit? Set aside for a minute what's legal and illegal, and just consider what entities are capable and incapable of. By using a DoH provider (that sees what domains your client IP is looking up) other than your ISP (that knows that your client IP goes with your real-life identity), there's now no single entity capable of associating your real-life identity with which domains you've looked up.