That’s simply not a great solution. You can’t make a fast paced fps feel good without trusting the client. Even quake has some factor of client trust. The issue is that even if the client sends just inputs across the network, you still end up with cheats that seems the exact inputs to click on a person’s head. You are trusting the inputs are sane. So that’s the raw metric of not trusting the client, it’s just sending the user data and the user data can be manipulated in order to cheat.
So you still failed to secure the game simply by trusting the client. It’s not possible and it’s an argument that comes from not understanding the technical challenge at play here.