Annual Reminder to Mix Up the Flash Meta
Let's see some diversity and renovation for Summoner Spells like we're seeing with everything else, new dragons, new maps, new champs, and so on.
Flash has been the dominant spell for 10 years. "But it's required" isn't an excuse. So many core features of the game have changed multiple times but Flash remains the same. If every champion requires a base-line of mobility then Flash doesn't have to be the only choice.
Mobility Spell + Functional Spell
If everyone needs Flash then just create two spell slots for Mobility and Function, then nerf Flash a bit and add alternative mobility spells to that slot while keeping everything else in Function. Or add Ghost to Mobility slot as well.
You could remove Hextech Flash and add a buffed version of it to Mobility. You could add a mini-Ekko Ult. You could add an ally-target Dash. You could add a non-global mini-shen teleport with no shield. You could add that thing that pushes you away from the enemy you're targeting. You could add an air-recovery to spin out of knockups and regain control.
If you have a mix of interesting options and a right amount of nerf to Flash, the Summoner Spells could be a lot cooler and more skill-expressive.