FPS counters are a very useful tool for developers or even gamers when trying to figure out the optimal settings for a game with their hardware. However I do not trust the kind of gamer who leaves their FPS counter on 100% of their game time. That kind of person is just looking for reasons to complain.
I once had an IRL conversation with a gamer complaining that the PC game he was playing kept dipping below 60fps on his brand new gamer PC and it was very frustrating to have to explain to him that the reason his FPS counter says 59 for a fraction of a second every once in a while isn't because the framerate is dipping. It's the same reason that every 4 years we have an extra day in the calendar. It doesn't mean the earth spins slower that year. Our systems of time measurements are inherently always gonna be a bit off and we need to sync them back with reality every so often.
