I love Flash! But...
It shouldn't be a staple. It should either be nerfed, or the other spells should be buffed, so it's not always Flash + [other spell of choice], at this point, and it has always been since as long as I remember playing League, Flash's position is similar to Homeguard's when boots enchantment were still a thing: everybody will take it no matter what.
What's the point of giving us 2 "customizable" spell slots if one of them is gonna be taken with Flash 99% of the time? Me and probably many other people would love if there were more viable ways to pick our spells.
would be garbage tier without