Install websites as desktop apps, so that they appear in their own windows separate from any browsers installed.
This is similar to the "Install as App" feature found in popular web browsers.

It uses an internal browser isolated from the system browser, which can optionally be used in incognito mode.
Links to websites other than the one installed open in a new browser window.

NOTE FOR UBUNTU USERS: Ubuntu has a bug that prevents Web Apps from working. A workaround is avaiable at
https://etbe.coker.com.au/2024/04/24/ubuntu-24-04-bubblewrap/ (see https://codeberg.org/eyekay/webapps/issues/15
for details)