What are your credentials with non-PHP, non-JS/TS languages? Have you written some Rust, Kotlin, Swift, ReasonML/ReScript/OCaml, Haskell, Elm or Clojure? Those languages are different to some extend, they take fresh approaches, they contain new ideas and are scrape throat well designed.
I find most cheering for PHP and JS have very little exposure to other camps of software development.
> PHP is probably the best language for server side webdev today.
I'm telling you (opinion ahead), it most likely is not. And most likely will never be. It simply has too many fundamental design errors that have long known solutions, are near impossible to fix in PHP/JS and are fixed-by-design in other languages that also have good tooling for web-dev.
This is not just PHP/JS. But since we are looking at "the best lang for webdev" I limit myself the these and this use case.