Monitoring software for a wide array of hw and sw

I'm looking into setting up some monitoring combined with simple automation for my selfhosting. Currently I was thinking about using Zabbix.
I want to:
Track bandwidth usage on a router/fw and on a managed switch and track cpu/ram/disk usage on my vms.
Simple monitoring (up/down/maintenance) on the router, switch, my vms as well as on linux services (jellyfin/forgejo/etc) and windows services (lab for studying work-related tools).
I'm also interested in doing simple https checks on my webuis (i've had a service running but the website returning both 403 and 404 before) and testing nslookup on my internal dns (if the service is up but the lookups timeout I still want to try restarting the service).

Is there any FOSS/FLOSS alternatives that I should look into before diving into Zabbix?