Guaranteed absence of flatpak will be a motivation for some to choose a non-systemd distro

And if not, it’s mtu

Tried it a few months ago, self hosted was free https://github.com/TwiN/gatus

(Otherwise uptimekuma or something, there are plenty of tools out there. If you wanna do it right 1st time for free : checkmk and or librenms, but it might be overkill for you just yet)

Basically this. You could start easy and basic with gatus. Monitor at least your gateway, the isp gateway and dns resolving.