I'm not sure why people use Bitcoin ATM's since they charge exorbitant fees of 5 - 20%+, though I suppose here's another reason not to use them :
They do generally have higher fees, but in some countries they are still not a bad way to buy/sell crypto.
For example, in Croatia we can still use BATM with no need for KYC if we keep transactions below 1k euro, and sometimes fee even drops to like 1-2% which is more than fair (mostly during bear market), and rest of the time its between 4-5% which is still not horrible due no KYC policy for smaller transactions. That probably won't last for too long though,