Just found my Vivaldi update contained a little more than just bugfixes… it now has Proton VPN built in.
It’s actually part of the browser, not an extension, so I’m in two minds whether I like that… or not.
You need either a Vivaldi account or a Proton account, so it’s not completely anonymous, but it’s a start.
The free-tier of Proton VPN also appears to be bandwidth limited and your exit point is randomised, so… yeah, it’s ok…
Don’t trust any cloud service to protect you from the authorities, trust the technical limitations you can verify. Proton is pretty good for this, in fact, one of the best. But like any service that wants to continue existing, they will honor legal demands for info.