Personal management system VS DashMachine

Have a look at this: https://github.com/Volmarg/personal-management-system

I don't know any exact app which you are describing but you could probably use either monica or Personal Dashboard . Both solutions are probably not perfect but better than nothing.

I dream of having some sort of home page with metrics about personal goals, calendar events, and other services. Because I'd like it to be open-source, I looked into Nextcloud, which is awesome but it lacks goal-tracking and a wiki, which I'd really like to have. I have also looked into "Personal Management System", which looks really interesting, but it lacks the community behind Nextcloud in order to earn my trust to use it in the long run. Ideally it would be awesome to be able to visualize all aspects of life, while retrieving this data from the top services of each category. Imagine a home page with a Kanboard from WeKan, storage from Nextcloud, goal tracking (maybe Nomie?), some notes in form of a wiki...

Personal Management System - https://github.com/Volmarg/personal-management-system

The very first reason of this project existence is my main project Personal Management System. My management system sole purpose is to work as a private data collector/manager and thus it should be always denied to access the internet connection. After further planing i decided that I can still forward the messages to another internal project and then push them into the ether.

A general-purpose web app for managing personal data. Like this but actually working and not as slow/buggy

I think you want Dashmachine or Organizr.