The post I replied to said "If I'm doing vias, I'm nearly finished with prototyping". You're not if you're using a QFN switcher which needs heat dissipation via the center pad. There's lots of cases of prototyping where vias would be handy.

> you cannot make much more than a basic breakout board

Except, you know, all the supporting circuitry, connectors, maybe microcontroller and JTAG header which could be put on instead of bodged together with random wires -- exactly the problem this is targeted to solve.

> Just the fact that you cannot have meaningful design over ground return paths with this thing makes any moderately fast digital link unfeasible.

You can with a 4-layer version, which is brought up in the video as one of the obvious improvements to make/try, and you would need/want the vias at least to route the other signals around your high-speed traces.