Fair, the actual M2 version linked would not be what would be used beyond convenient development.

The actual TPU chip itself from the M2 card is sold individually as a surface mount chip and that is what would be used in a "serious" design.

https://coral.ai/products/accelerator-module

I did a cursory search and I can find zero other products that compete with that module, within an order of magnitude of power consumption/price/etc

At this point, nobody sells modules for this, and I doubt many coral chips still sell. The current slot for an ML accelerator at about 10 TOPS is as a peripheral on an SoC. Most serious SoCs have one.

In other words, the reason you didn't find a commercial competitor to these things is that the competitor is (nearly) free.

Here's one vendor: https://www.ti.com/technologies/edge-ai.html