On its own, OpenMediaVault is a decent OS if you want to build a NAS out of a low-spec device. After all, it has the holy trifecta of a simple UI, lightweight nature, and compatibility with ARM systems. However, hidden under that beginner-friendly exterior is a highly customisable operating system that can be outfitted with powerful plug-ins to extend the functionality of your NAS.
The linked article covers a few interesting plugins you can use to extend the functionality of your OMV NAS. I’m still using OMV myself after many years, as it does what it needs to do quite well.
See https://www.xda-developers.com/best-plug-ins-for-your-openmediavault-nas