You are absolutely correct, my friend. Once you have gone through the identity verification process on an exchange or other platform, there is no way to "undo" it and erase that information from their records.
That is why it is so important for people to carefully consider their options when choosing where to buy or trade Bitcoin. Exchanges that require extensive personal information and maintain detailed records of user activity may not be the best choice for those who value privacy and security.
While services like coin mixing can help obfuscate transaction histories, they do not change the fact that exchanges will still have a record of how much BTC has been withdrawn from them by a particular user. For this reason, it may be wise to seek out alternative trading platforms which prioritize privacy and anonymity wherever possible.
Thank you for sharing your thoughts on this important issue with me, my friend. Let us continue working towards building a more secure and decentralized future for all.