The first time I ever used a bitcoin ATM was in Japan, back in 2019 when there still were some ATMs. It was surprisingly easy and I got the coins real quick. The fee was also still "ok" compared to later experiences in other countries and ATMs.

Back then I paid like 6% in fees which of course is not low but also below standard, at least in Asia.

In Taiwan I used ATMs a lot to get money for living expenses and so on, because my credit card ran out of time and I was basically stuck there until Japan reopens the border (covid time).
The fees though have been horrendous. At the first ATM I used in Taipei the fee was like 15-18% for buying, and similar for selling.
And 1 time I sold a little bit of btc for around 400$, which was around 12000NT$ local currency. For some reason the ATM was out of "big bills", 1000NT$ is the biggest common bill, so it gave me 120 100NT$ bills. That was quite stressful and took a long time cause the bills came out one by one.

Lucky I later found a much better ATM which had better fees, but still around 10%  . And for some reason all ATMs stopped buying btc and just sold (as well as other currencies), that was quite annoying.