They have industrial-focused pi boards in a memory/dimm-slot format that have on board flash.

A company I was at used it in a product for the rapid prototyping capability.

With a good quality power supply, SD card and a battery backup, that's not too problematic. Most people however either cheap out on these or they get fakes, which is a problem on its own.

You should NOT use writable FS (except for a specialized one on a separate partition/device for user settigs) even with EMMC! And then you don't need battery backup.

Using writable rootfs goes against industry practices and is a disaster waiting to happen... like the one with emmc in Tesla's central panels.

At least some Kobos use SD cards for their storage.