I feel @AstonJ is spot on in his analysis.
To answer @wolf4earth, I don’t have a personal experience and I am cautiously optimistic. It can be seen as a fad especially when you see youngsters immediately jumping to use it… with Node.JS CLI apps. 
Cold starts can be a serious problem. So languages that compile to native binaries – and don’t carry a huge runtime with them that needs a bootstrap on every app start – have an advantage. Off the top of my head, people had positive experience with “cloud functions” in C, C++, D, Rust, Zig, Golang, Nim, OCaml, Haskell, likely others as well. Not so great luck with dynamic languages, Erlang/Elixir included – JS and Ruby weren’t in great shape either, Python and PHP are also rather slow to start.
I’m open to the idea but I’d think that you have to reshape your app and services – likely even your business – to make serverless [cloud functions] work well for you.
One area I am hugely skeptical is that the big vendors will do their absolute very best to lock you in their garden. So the idea is good but I feel is being weaponized for business interests.
That, plus many people really love their JS and don’t want to learn languages like C/C++, Rust or OCaml, which have one of the very best startup times: <4ms for a hello world program. So in the end I posit that the idea might die simply because the JS runtime (Node.JS) can’t be made to start so fast.