I only have experience with nagios 🥹 Been using it for the better part of a decade.
Discussion
I went from Nagios to Zabbix all pretty time consuming. With cloud stuff have their CloudWatch or equivalent so use something like Uptime Kuma for remote checks. At home use Glances now. 🤙
Nagios is good. But was thinking for like a few servers, needs a rifle not a Howitzer 🤣