> Besides, I don't think anyone really has a local network which is faster than their SSD. Even a 4-year-old consumer Samsung 970 Pro can sustain full-disk writes at 2.000M Byte/s, easily saturating a 10Gbit connection.

You might be surprised if you take a look at how cheap high speed NICs are on the used market. 25G and 40G can be had for around $50, and 100G around $100. If you need switches things start to get expensive but for the "home lab" crowd since most of these cards are dual port a three-node mesh can be had for just a few hundred bucks. I've had a 40G link to my home server for a few years now mostly just because I could do it for less than the cost of a single hard drive.