I brought up this topic because I want more explanation,if there is any development or means outside of the public Blockchain that also stores client data to ensure more privacy. I also learnt about lightweight wallet that connects to full node before any transaction,why is it so.....
By increasing the number of places where the client information is stored, you are not ensuring the privacy of those clients, you do exactly the opposite: you widen the attack surface by artificially creating additional points of failure. All transactions in the Bitcoin blockchain are pseudoanonymous in their nature, but you can increase the level of anonymity by employing third-party services, solutions or wallet features such as CoinJoin, CoinSwap, regular coin control, and by paying attention to transactional hygiene.