The mention of esata for this application, was chosen for its synthesis of these features:
1) low barrier to entry on the construction of the enclosure. Just a COTS industrial PSU, and dumb cables, in a 3D printed box.
2) Inexpensive interface cards or SATA port adapters for use with ESATA cabling are readily available, and can easily go in modern systems. (Even very modern intel Z790 based SATA controllers support using ESATA cables on such adapters in this fashion. It being "A thing" is accurate, even if very few people actually make use of the capability. It is *STILL* present. What is *NOT* supported, is port replication. Again, the major outstanding issue with ESATA, was that there were competing standards for port replication , and most sata controller makers did not pick a horse in that game, and instead just said "NO PORT REPLICATION." (which is what is the case with the cited intel Z790 chipset SATA controller. NO Port Replication! Period!) As long as you run 1 cable, to 1 drive, that ESATA dumb external cable will work just fine. If you note about the listed, dedicated ESATA card, however, it DOES support port replication (FIS mode), meaning you could use a SINGLE cable, and stuff a port replicating backplane inside your enclosure for a simple 5 bay enclosure, like this guy. Just be aware that it WILL NEVER WORK on a sata controller that does not support Port Replication, which is basically any internal baked-on SATA controller. You'd need the adapter card for it.)
3) Vintage optical drives WILL NOT saturate SATA-2. (A 16x DVD has a theoretical maximum sustained thruput of ~21mbyte a second, which is below even ATA-133 speeds. SATA-II tops out at 300mbyte/sec. That's quite a bit of room.)
4) ESATA is agnostic of whatever the hell you put on that SATA->IDE bridge, meaning you can put that LS120/Jazz/Tape/Zip/Whatever drive in there just fine.
If you want to jam a whole lot of modern spinny disks inside to make a NAS, you are better off with an industrial chasis.
USB3 is "No interface purchase necessary!", and "Is MUCH faster than ESATA!", but suffers from "Needs a very intelligent, and thus very pricy controller card inside the enclosure itself, and with a much lower potential for putting any old drive in there, and it working as expected."
Please stop being hung up on this.