- https://openalternative.co/

- https://www.opensourcealternative.to/

- https://opensourcealternatives.org/

- https://www.btw.so/open-source-alternatives

By just aggregating everything FOSS, doesn't mean its useful. Its useful in a certain context - such as searching for alternatives.

If you are uncertain how to "plan the product", don't plan -> just start.