Proton is a good service, but their years of reluctance to include more anonymous payment methods such as Monero and the inability to register an account from an anonymous IP address without a phone number makes me question the relative benefit of using them as a VPN.

These do not by themselves result in a compromise of anonymity if Proton is trustworthy and the Swiss laws still enable them to disassociate your identity (given via payments) and your account usage, but regulation and governments tend to become stricter rather than looser over time and I would demand more from a service you are entrusting with all your internet traffic.