Flash balance idea

So I had an idea, and I think it can help with mobility creep a whole lot if implemented. Now the exact numbers and values would need to be worked out, but this is the basic idea.

What if the cooldown of flash were to increase with the use of dashes, blinks, etc? Each time a mobility tool is used, the cooldown of the next flash is increased making flash a weaker spell for anyone with already strong mobility. This would also leave imobile champs uneffected so it can still be a strong spell for them.

Thoughts, opinions?