Like many around the world, as 2022 ended I looked forward to watching the World Cup. One day, I was watching the World Cup on my phone while walking my dog. As Team USA was about to score, I walked out of my Wi-Fi range, and my phone switched to a cellular connection.
If your users are on reliable connections, or your site or app can already handle dropped connections, you probably don’t need HTTP/3 right now.
There are caveats; for example, Fastly supports client connections to Fastly using HTTP/3 but not between Fastly and your origin servers.