@Riot: You're creating unique Champions, but you're missing something:
Mobility vs Non-mobility 
Nearly every new champion has at least one flash/dash/boost in their kit. I'm not calling these champions overpowered, simply stating that they have built-in mobility tools.
Don't get me wrong, I love playing a lot of these champions. But, many of them have very reliable mobility, without very reliable counterplay.
It's time for a new summoner's spell.
- Disable:
- This new spell should disable flashes, dashes, jumps, without affecting anything else on the target.
- The target will not be slowed or damaged, but simply be unable to use any such abilities until the effect wears off.
- Damage/heals/other abilities are unaffected, ONLY mobility tools are deactivated. Once the effect ends, these spells can be used normally.
(FAQ)
- L2P instead of asking for nerfs!
I'm not asking for any nerfs, or changes to these champions to be made. I'm asking for Riot's champion design team to try a little bit harder to make unique champions without throwing 400+ range flash/dash/boosts with little or no cooldown into every single kit.
- You mean you don't want them to change any of these champions? But __ is overpowered!
This thread isn't about nerfs/buffs for champions. This thread is about mobility as a whole.
- Flashes/dashes shouldn't be able to be countered by a 210ish cooldown Summoner Spell
vs Regen
vs CC
vs DMG
TL;DR: Having a healthy game is about having clear, defined weaknesses to each strength. Paper beats rock, rock beats scissors, scissors beat paper. Without a balance, your game becomes unhealthy.
If Scissors were instead Industrial-Strength Lasers, then no one would pick Rock or Paper! And now, flashes and dashes are League's form of Industrial-Strength Lasers.
