This one does not even make sense - 100 megs for a binary for centralized metrics? Who would even notice next to the OS and metrics storage.

By design you should not install prometheus on every server you monitor - it's designed to scrape metrics

Its a database, webui with support for email, webhooks, slack, pagerduty, aws api and many others. 100megs does not sound like a lot for all Pormetheus provides