Would Mordekaiser still work without his isolation bonus?

This champion is incredibly overtuned right now and I don't think people are trying to deny that.

I was thinking of what could be done about this, and I never really considered it, but why doesn't Riot just remove the isolation bonus he gains?

I understand his ult pairs with it, but why should it?

A lot of the problems in league come from Riot's philosophy of every kit needing cohesion, but all it does it eliminate a lot of counterplay you could have when fighting these champions.

For example, Pyke:

His Q pulls them and then slows them by 99% for 1 second. The slow makes sense because it lets him combo his e and hit them.

Another example, Akali:

Her passive gives 40-70% movement speed for 2 seconds while moving away from the enemy so she can use her passive more easily.

Both of these make sense, yes, but if you were to remove them, it would give more counterplay and actually take skill to use these champions.

Pyke would need to predict his e to where they might dodge and Akali would need to hit her Q perfectly to get the empowered auto without the enemy just walking towards her to stop it.