You become historical powers over time. After two decades of being run well and with good seasons, Leicester can be one of those clubs. Leicester are a one club city with very few big clubs around their catchment areas, West Ham easily could become another City as they have a huge support.
Arsenal are going one way... they’re poorly run. They are the epitome of a mediocre modern football club, and after a few decades as such, their elite years will be an afterthought.
That’s the good thing about football.