Earlier quoted context omitted.
Giving state isn't the problem, the client being authoritive is the problem. What I'm describing is so-called rollback based netcode, the server should always keep an canonical state and deviating from it is at a clients peril.
Giving full state is still a big problem. Aimbot, ESP, wall hacking are possibile only due to giving full state to the client. Most competitive games avoid this as much as possibile, eg. Dota2, Valorant, etc.
- Aimbots is a problem regardless of state it, as long as you can see/shoot at it then aimbots can exist, stopping that is a separate issue.
- On ESP/Wall hacking you're right, it can be an issue
- Full snapshot/heap shipping as emulators and Kettlewells WASM sample is hard to patch here.
- an DoD ECS grounded design like Ambient could selectively withhold entities (ie out of sight), however I think for starting development it shouldn't be an initial worry as long as you don't design yourself into a corner in such a way that it's impossible to implement later.