We’ve been using the free ESXi ghettoVCB backup utility for the last 5 years to backup about 150 VMs daily without a glitch. ghettoVCB snapshots the VM, copies away the files (with a configurable retention period) and then removes the snapshot. The resulting backup is a snapshot of the VM which means that when you need it, you can directly run the backup copy of the VM with ESXi and start it without having to restore it. ghettoVCB is fast and reliable (it copies sparse disks correctly to an NFS backup share so the resulting backup is as compact as the original VM disks).
ghettoVCB has no deduplication capabilities, so its usually not appropriate for offsite backup of VMs. We use borg to archive the ghettoVCB backups offsite. This has the advantage that you get indefinite retention offsite (since borg does very efficient deduplication). You can also mount any borg backup (using its FUSE mounting), so you can run any backed up VM straight out of the archive.
ghettoVCB is available at https://github.com/lamw/ghettoVCB