JoshyPHP Stories and assumptions aside, the serverless concept is being accepted with open arms by large corporations. That does not mean that it's the right way, but it points to where the future of development and hosting is.
I'm ready to accept that future, are you?
As far as Flarum goes, I think I've repeated myself many times and therefore, this will be the last time. Flarum might not necessarily gain on performance if it was implemented in the serverless fashion, but if you already have a large infrastructure, with many websites and databases, all built serverless, you will probably not go back to the server ways of doing things just to accommodate the use of Flarum.
My suggestion mostly has to do with what the future brings and that is cloud and serverless. If Flarum does not prepare for the future, that is pretty much just around the corner, it might be dead on arrival, and I'm willing to bet nobody here wants that.
This was a word to the wise, peace.