Comment by _kb

There's a bit of a trend of vendors packaging mobile CPUs in desktop form factor which are a good candidate for this. Rather than the prebuilt mini PCs this also includes mini-ITX boards. Personally I use the Minisforum BD795i SE, but there are others too.

Check for PCIe bifurcation support. If that's there you can pop in a PCIe to quad M.2 adapter. That will split a PCIe x16 slot into 4 x M.2s. Each of those (and the M.2s already on the motherboard) can then be loaded with either an NVMe drive or an M.2 to SATA adapter, with each adapter providing 6 x SATA ports. That setup gives a lot of flexibility to build out a fairly extensive storage array with both NVMe and spinning platters and no USB in sight.

As a nice side effect of the honestly bonkers amount of compute in those boards there's also plenty of capacity to run other VM workloads on the same metal which lets a lot of the storage access happen locally rather than over the network. For me, that means the on-board 2.5GbE NIC is more than fine, but if not you can also load a M.2 to 10GbE adapter(s) as needed.