This is what I recommend too, but for those who want something prepackaged, there's also XigmaNAS, basically a lightweight UI layer and basic configuration on top of FreeBSD. Some of the original FreeNAS developers have been working on the project for almost 20 years.

It's great for people who just want storage and don't want the heavy features that came with TrueNAS' move to Linux (Kubernetes, etc.) or who want full control over vfs_fruit options for serving Macs.