I found this very promising app that looks like it can be an alternative to Ferdium, Rambox, Franz, Hamsket.

WebSpace is an app that brings websites and web apps together in one organized, streamlined interface. Any web app you can think off can be used in WebSpace in its own web instance instead of your main web browser. Basically it is a web browser but for web apps you use often and may want running in the background.

For use degoogled users who use website, web apps, PWAs over native apps, this makes using these services much easer.

WebSpace also adds many privacy features such as ad blocking and filtering, cookie isolation, and more.

Also it is written in Flutter! Meaning this could become available on desktop in the future! One app, one codebase for all major OSes!

Check it out and contribute!