From what I understand, PTACs started as a convenient way to retrofit apartments with air conditioning. You don't need ductwork, which I believe is more expensive in the concrete buildings around here. Also, I think you need protected refrigerant sleeves to meet code here, but only if the sleeves go from one floor to another (someone just told me this fact today, and i haven't verified this).
BTW that PTAC's thermostat dial in the link doesn't have numbers around the dial, which I think is honest. No A/C unit I've ever owned has managed to have a thermostat that read the temperature I was feeling consistently. It makes me think the apartment was built before the late 2010s though -- still feels new but a generation ago in HVAC terms. Mini-splits seem to have arrived, even for <1M condos. Talking to the mini-split contractors I had over recently for a squeaky noise, I got the feeling that business was booming. They had every day in the summer booked months in advance.
When I lived in the US I tried to get a minisplit and they wanted $4000 for a medium size unit! The same one where I live now is $400 installed.
The situation with R-22 (better known as "Freon" in the US) seems pretty messy and confusing. https://en.wikipedia.org/wiki/Chlorodifluoromethane#Phaseout...
As far as I can tell, the import of the R-22 refrigerant itself wasn't banned until 2020.