Self-hosting seems easiest to think about as a home appliance.

Out of compute, storage, database, networking, etc, which is most preferable to be just an appliance?

It's pretty reasonable to get reliable storage self-hosted without the headache. If a big setup isn't needed, it's reasonably attractive to set up your own storage with reasonable power draw, which can be kept up with more reasonable UPS'.

Just because one can build and run a storage array on their own, doesn't mean it would be the best allcoation of their ongoing attention to maintain and be on call for a daycare for hard drives.

If seamless storage as good (and sometimes better) than a cloud is the minimum, it has to be something trustable, and run like a reliable home appliance needing minimum maintenance.

Lots of folk choose NAS enclosures that have raid mirroring and hot-swap drives built in quite inexpensively using things like Synology or QNAPs. The web admin interfaces on them are reasonable, and it's trivial to poke along with a youtube video to setup a RAID 5-10, and send email notifications how you like if it wanted to bring something to your attention.

Other things that become way more valuable over the years:

- NAS can be configured to backup offsite to the cloud backup of your choice, or another NAS. I know folks running them for 5-10 years and never think about it. Decent NAS with appropriate drives, secured of course. Some people even mail the enclosure to a datacenter and have them plug it in and keep it online.

- If you get a reasonably basic NAS with an intel Celeron CPU, power usage can remain low, but ram can be upgraded on it to run a few services as needed on it, both directly, and as docker images. It's pretty wild.

- If you do consider it, my recommendation is to pick one that has 2 extra drive slots than you need, and start from there. People who buy two bays can outgrow them quick, plus it's only a mirrored raid between two drives. Raid 5 and higher is great, if one drive is starting to have issues, you can just swap it while it's all running and the storage will heal.

Hope that helps. Having data close to crunch can be valuable.