[Androider]

Turns out it's not really an issue in practice, since you rarely serve naked Node.js to the Internet. If you put something like a load balancer (ELB) or reverse proxy (Nginx) in front of your service which speaks HTTP/2, you already get 95% of the benefits. I expect HTTP/3 to likewise just be a toggle offered by AWS/GCP/Azure/NGinx etc. in the future, and your users will see an immediate benefit.

[steveklabnik]

Cloudflare includes such a toggle for HTTP/3, though to be honest I forget if it's still in a closed beta or more generally available.