Been using 1Password since 2010. I tried Bitwarden a few years ago just because of the price. In theory it ticks all boxes but it was a pain to use. I does not flow like 1P, some things did not work the way I expected and it looks like shit. Don't ask for details because I forgot. So I switched back. The new design of 1Password made it a little worse but it's still great and the integration into iOS and macOS is amazing.

buttercup.pw

Disclaimer: I’m the developer

It’s been a long time since I switched to 1Password, but I used to use keepass. I’m not sure whether keepass has a browser extension, but otherwise (if I recall) it checks your other boxes.

1Password is great, even though it’s not open source, and you get to a spot in life where $3/mo is feasible.

You can use SafeInCloud.

Selfhosted or not, you can also make keepassxc portable with a usb drive.

Here is a old thread from redit explaining how to do it:

Dude.... KeepassXC has portables for linux, there is no need to mess with wine or mono. As long as you have both portable versions of KeepassXC, you will not have a problem. You can totally have your database sync between OSs.

• For Linux, just get the AppImage for the portable.
• For Windows, get the Portable ZIP archive.
• Shove them both into a USB, you have KeepassXC portable for both OSs on a stick.

Source: https://www.reddit.com/r/KeePass/comments/10i8joq/keepassxc_portable_on_windows_and_linux_or/-