Nature itself is literally making new covid versions.

And our immune system detects and fights most of them similar to how virus scanners can detect a virus it doesn't know. By detecting similarities.

If a new variant comes along that is so different from the OG virus that your immune system doesn't know what to do with it, they develop a new vaccine, which you have "install on the client side" by getting the vaccine, to protect you from getting sick from it.

If new methods are developed to cheat, the cheat engine gets updated to detect those too.

As for "brief dip", that's the only thing needed for a product launch.

If a game is rife with cheating day one, it'll fail.

If it only gets rife with cheating when people are already invested in it, the cheating is much lower priority.

That doesn't change that fact that at the server side, you're unable to detect most prevalent forms of cheating.

Wallhacks and aimbots are nigh impossible to detect on the server side.