This is already required, even for person-to-person transactions. Coinbase, Gemini, and Kraken do this. However I find it highly unlikely people do this volunta

This is already required, even for person-to-person transactions. Coinbase, Gemini, and Kraken do this. However I find it highly unlikely people do this voluntarily or will do this now voluntarily. Tools like Tornado.cash make it easy to “warp” funds into Defi land and then back out later with plausible deniability.