I use Veeam Backup & Recovery Community Edition. If you’re runing VM’s you have to be on VMWare or Hyper-V. You can also use agents on the individual VM/Server. It also requires a pretty hefty Windows host, at least if you want your backups to complete fairly quickly.
Those are understandably downsides for some people. But, Veeam is in a class by itself. It has no serious competitors and as far as ease of use and reliability, it’s top tier.
I’m lazy. I don’t want to spend a bunch of time configuring finicky backups only to find out I needed one and it failed. I honestly wish there were a comparable open source backup system. I have yet to find anything that works as well.