Q: do you ever feel reluctant to change the key of a song - even though it would be objectively useful - just because you kind of feel the song 'has to' be in, say, F Major?
A: usually not. more often there might be a requirement that it must NOT be in a particular key, because the previous song was in that key. The only situation i can think of where a song needs to be in 1 particular key is if the song was specifically written around, and featuring, some widely identifiable real-world sound effect. like the boink noise in everyone's favorite video game