We already have that. For eg: https://www.btw.so/open-source-alternatives/slack-alternativ...
But when I go to, say, https://www.btw.so/open-source-alternatives/api-documentatio..., no where on that page does the word "Swagger" appear. Same story for https://www.btw.so/open-source-alternatives/business-communi... and Slack.
It seems like you already have the data, so it would just be a matter of finding the right UI for it.
Edit:
Now that I look real closely, I see in a tiny box on each alternative what the each thing competes with. I guess that works. Kind of obscure, though.
Disclaimer: happy (paying) Odoo customer!