Solving it on the client is literally impossible, solving it on the server is difficult and could be impossible, big difference.

It's like someone trying to send a car to the moon by pulling the steering wheel. It's impossible, the fact that building a rocket is hard or that you don't know how to do it or that it could fail has no bearing on the fact that trying to pull the steering wheel on a car is definitely the wrong way to go about it.

In the same manner solving cheating on the client is the same kind of impossible, anyone defending it sounds like a flat-earther to anyone with the basic knowledge of client/server architecture.