I am wondering is it truly possible that my BTC works for me , without revealing my private keys and also without KYC ?
I have read and heard about similar things but they seem more like a Ponzi scheme.
Does anybody have any experience with a non-custodia platform/wallet /swap which does not require KYC but supports BTC ?
Yes, it is very possible. Often times we heard phrases like let money work for you, that means investing or something you put money onto something and then you earn a passive income, there is also no difference with that if we are talking about bitcoin because bitcoin is also money anyway but there should not be revelations of private keys, passwords and other sensitive details because that is a sure fire way that you will loose your btc's or will only get scammed but for the kyc part?
It might be needed especially if your dealing with centralized or formal companies but you should not worry as long you gather information that they are trusted, you should try them out.