It makes no sense (in serious games and tournaments) because computer analysis quickly reveals the use of third-party programs. Strange as it may seem, the player's chess behavior is very easy to predict, and if he "suddenly" starts to play better than his level, this immediately attracts attention.
But what if the player uses third-party programs from the very beginning? Then the computer will not be able to notice the change in the player's behavior and determine that his level of play has changed. The computer will perceive this as normal chess player behavior.
Firstly, all strong chess players from the very beginning of their careers play in live tournaments where cheating is as complicated as possible, almost unrealistic. Secondly, even if you cheat all your life, you will be caught on the fact that your analysis is statistically too close (unlike other players) to the computer one.
In addition, if a player plays games as first lines of chess engines, then he automatically receives a ban on almost all chess sites.
This surprises me a little. Chess engine programs are written by people and loaded into it with standard moves, combinations, debuts, that is, everything that was used or is used by chess players. Any average chess player can use one of these options, but this does not mean that he is a cheater and there is no reason to ban him.
You are probably far from the world of chess and from computer analysis. Firstly, modern chess engines are neural networks that have learned themselves and have nothing to do with "learning" from people. Programs written by people still exist, but this is the previous generation. Secondly, computer programs offer such moves that ordinary "protein" players have not even dreamed of, this is easy to identify.