I recommend it for serious work. Well, serious enough that I got paid for doing it, and/or given talks about it.

(not if you're only doing x86/ARM stuff, though)

Agree. IDA is surely the “primary” tool for anything that runs on an OS on a common arch, but once you get into embedded Ghidra is heavily used for serious work and once you get to heavily automation based scenarios or obscure microarchitectures it’s the best solution and certainly a “serious” product used by “real” REs.