It's a simple answer it's safe, majority of these countries sex work is regarded as a career. Mainly I think it's the safety aspect of being in a developed and non-ignorant society. A Ts Escorts need to be comfortable in a country where the law will protect her and be the same for anyone no matter sexual preference or gender.
The draw of European countries they are more developed than other parts of the world. Is a massive attraction to Ts Escorts. Of course like in any country, you will always find bigoted people, But as I mentioned before the law prevents them From being any more than that.
Another appeal is the location of Europe it's one of the most visited continents in the world. Which can only be good for business. It's easy to connect and traveling in-between European countries make it a breeze.