You mean this solo chess?
https://www.chess.com/solo-chess
It is just a silly game to play by yourself - not really chess at all and more like puzzles if you've played it. Personally, I've played it a few times, but not a ton because it is really easy after a while - even crazy mode is fairly simple once you get used to the game.
I do stuff to make it tougher for me just to make it more challenging lol
Sometimes I'll calculate EVERYTHING I'll play before moving the first piece and then completing the moves at bullet speed. Other times, I'll just move on intuition without much calculation etc.
I think it is just a fun "variant" (I'll call it a variant since it isn't really chess) to mess around with for a change of pace. What you could get from it is probably calculation practice if you used it for that and maybe tactics in a sense, but I don't know much else playing solo chess would help you with 
Hello guys,
I just had a silly question that's what actually solo chess is? And what is it's use?
What can we learn from it?