That's not true at all. Synology will sell you 24 bay rack mounted devices and 12 bay towers, as well as expansion modules for both with more bays you can daisy chain to them.
Granted, I believe those are technically marketed as enterprise solutions, but you can buy a 12 bay unit off of Amazon for like two grand diskless, so... I mean, it's a thing.
Not saying you should, and it's definitely less cost effective (and less powerful, depending on what you have laying around) than reusing old hardware, but it does exist.
None of that really matters for a home media server. Even the limited SATA ports, worst case you have to grab a cheap expansion card.
Power consumption is a much bigger concern, a purpose built NAS is much more efficient than a random old PC.
Even the most expensive Synology only has space for 8 drives with only one 10Gbit ethernet port.
You can build something yourself for less with much better performance.
And more freedom.
That's not true at all. Synology will sell you 24 bay rack mounted devices and 12 bay towers, as well as expansion modules for both with more bays you can daisy chain to them.
Granted, I believe those are technically marketed as enterprise solutions, but you can buy a 12 bay unit off of Amazon for like two grand diskless, so... I mean, it's a thing.
Not saying you should, and it's definitely less cost effective (and less powerful, depending on what you have laying around) than reusing old hardware, but it does exist.