Market forces alone didn't work. It's an externality, a cost paid by others not involved in the transaction. Market forces don't handle that. A 1970s Milton Bradley Big Trak and a Radio Shack TRS-80, both popular products in their day, will, if brought near to each other, both crash. Without fairly strict regulation of unwanted RF emissions, there would be many incompatible devices. There were before the FCC started requiring more testing in the 1970s. A world with a huge number of consumer devices emitting RF noise would have prevented low-power cellular phone and WiFi deployment.
It's not that hard. This is an "unintentional emitter" (it's not trying to send a radio signal). The rules for that are not too bad. Testing costs about $3000 to $5000.
You want to have some ability to pre-test. You might find something. Attaching a wire to something can give it an antenna and make it emit much more RF, so you do need to test. It's not too hard.[1] Actual FCC certification is $3000 to $5000, assuming you pre-tested and fixed any problems before getting a certification run.
From the project's FAQ:
"Given that this will initially be a niche product, the price will be quite high. I was once taught to ask myself the following question: Who is your rich customer? The type of person whom I have in mind has a high discretionary budget for personal electronics and willingness to pay a premium for novel ideas."
[1] https://www.nutsvolts.com/magazine/article/low-cost-emi-pre-...