For any transaction worth a damn, you had to register an account online, provide ID, etc.
You would get a code via SMS when you used the machine to authenticate.
A few models had a built in passport scanner type thing and webcam, another had a fucking fingerprint reader.
It was pretty much the same level of KYC/AML you needed to transact at Coinbase or Kraken, but you could input or receive actual paper cash, which seems to have upset the regulator so those machines went away as well as the no-KYC ones.
I don't think most of them have any kind of Chainalysis setup or that would kill the margins for most of the operators. Isn't it basically just a license scan, SMS code, and daily/monthly limits?
I assumed they went away because they combined the fat markups of bitcoin ATMs with the KYC inconvenience of Coinbase.
Why would you pay punitive fees to an ATM operator to get bitcoin if you could just deposit the cash in your bank and buy 'normally' for many % less with a card/bank transfer?
The haircut is so large on those machines that the only use cases at the moment are financial crimes.