With Caddy[0] around, the only thing that keeps me tied to nginx is its performance and tried-and-tested-ness.
Waiting to see someone do some detailed benchmarks on Caddy before I commit to it for production stuff, because I'm too busy and too lazy to do them myself and I have a while left on my paid TLS certs.
I mention Caddy because it includes LetsEncrypt and HTTP/2 out of the box — and is written in Go.