Mullvad has a decent Linux GUI, but you have to install their service. On the positive side, it works with and without systemd.

Just had a similar experience with Bitwarden. Works flawlessly on every device, but the linux vesion doesn't integrate with the browser (the app not the browser extension). I also had to do some special tinkering to make it accept self-hosted vaultwarden with self-signed certificate, because electron apps on linux don't use the internal's system trusted cert store ? Nah, you have to install certutil, and add it to a "sql database"... ⋮/

And i'm just starting as a linux power user, and it already begins to show why linux isn't "there" right now... But I don't see it as something bad, quite the opposite, linux is supposed to be flexible, open source, a playing ground for nerds... But people's desire to overcome GAFAMS monopoly slowly turns linux into something I hope won't hurt the community or make them part of GAFAM acronym...

I also had a similar experience with Nordvpn.

That's one the commercial software providers, not Linux