There are several public lists out there that list known VPNs such as:
https://github.com/ejrv/VPNs
https://udger.com/resources/ip-list/anonymizing_vpn_service

There are also paid for services that have a lot of API back end automation:
https://www.ipqualityscore.com/vpn-ip-address-check
https://www.maxmind.com/en/solutions/geoip2-enterprise-product-suite/anonymous-ip-database

All using a VPN does is hide who you are, it does not hide that fact that you are using a VPN.
And since many of the services are on known IPs it does not even hide which VPN service you are using.

-Dave