Not OP, I’ve heard criticism of their recent Duo subscription and their bitcoin wallet.
I use Proton services and my biggest gripe is their mediocre Linux VPN app. No binaries to download/Flatpak, advertised port-forwarding isn’t fully implemented and requires playing around in a terminal, and UI feels less polished than it’s Windows counterpart.
There’s a community made Flatpak of ProtonVPN though, in case it helps anyone