Yes, decentralized exchanges can be used from anywhere in the world, and similarly no KYC instant exchanges can be used by anyone from any part of the world without any kind of restrictions. I think for such data it's always better to read posts in this forum because here users are very smart and they know everything about such services and they can explain those things in way better words so others can understand those without any issues.
When it comes to AI, then still we can't trust it fully because sometimes it gives wrong information, however I must say that nowadays AI is much better than it used to be in past. Those who use services like Dex.fo know better that privacy is a very important thing, and they'll always prefer to use instant exchanges over those KYC exchanges.
Yep, we can't trust AI results either. Even if we are using an advanced AI model which gives us the result after taking some time to do thorough research, it will still show us exchanges that are famous and have been in the market for quite some time. I won't name them, but if you have AI, you can check.
The problem with this is that some of them, or most of them, are not really no KYC or no AML. They eventually raise flags. So from a newbie perspective, it can be hard. They will eventually look for directories like KYCnot, Bitlist, etc. These directory sites are a better option than AI.