Bro you are making zero sense. VPN usage makes your choice of website private to your ISP and VPN usage makes you anonymous to the websites you visit.
Your internet connections will never be private to the websites you connect to and the fact that you are using the internet at home will never be anonymous to the people providing that internet access to your home.
Obviously my ISP knows that a certain "Scott Undrel" is using ProtonVPN. In fact, it brings me joy to know that my ISP has to sit in the metaphorical cuck chair. And obviously Proton knows who owns the email account ScottUndrel@Protonmail.com. The government already has my real life address, so why does it matter if they also have my IP address?
Whenever I need to make actually anonymous Protonmail accounts I just use Protonmail's .onion address.