I don't see the problem with kits.

They are easy to get for all players. You don't have to buy gold-or silver boxes, you don't have to pay tokens (except multi-kits) and everyone can get them.

I lose almost the same amount of battles that I win due kitting.

This match my opponent use kit and wins.
Next match I use kit and win.
And another match we both use kit and are even again.

Really, I don't understand the problem. I'm not winning more or less battles than before. I just spent more SM on kits and less on boxes.

Kits are part of the game. Deal with it. It's nothing just you opponent gets an advantage from. You can use them too.

Mythicals are a bigger problem imho, cause here are the chances to get them not even.