>>528264136
If you're talking about modern firearms, then sure, but a simple rifle is not only very inexpensive to make, but also ridiculosuly simple to the point african mudwellers can manufacture them. Granted, some basic gunsmithing knowledge is required if you don't want the thing to blow up in your face when you pull the trigger, but with that said even a literal monkey can figure out how to use one.
If you compare that to the time spent figuring out how to send a fireball without imolating yourself, I'd say they're quite worth it.
That being said, I do agree that the vast majority of firearms depiction in fantasy settings are handled very badly.