This comment has a real grain of truth to it: reducing request load on your users has way more bang for the buck than changing protocols.

At my company we did a test for HTTP2 and HTTP3 versus HTTP 1.1 in South America on a 4G connection. We found that Netflix loaded in less than 2 and 1/2 seconds regardless of what protocols the client supported.

We determined that if we enable the HTTP2 or 3, We would save perhaps a second or two load time, but that if we reduced the request load we could perhaps save on the order of tens of seconds.