They offer a money back guarantee, cover the likes of surfing, diving, trekking and bikes (which many don't as standard) and you can buy from any country in the world.
Cheaper policies are fine for the important health aspect, but don't expect to have your US$500 camera/laptop, a dive or any previous medical condition covered.
Conversely even on more expensive policies, don't expect your US$1,000 camera/laptop to be fully covered unless you have made special measures for it.
Moreover many parts of Asia or the Americas are now just as advanced/civilised – if not more so – that the West.
It is all very difficult to know what is fact and fiction. With so much to take on board and so much trepidation when you may have have never travelled before it is no wonder that so much money and time is spent and wasted on jabs, pills, visas, insurance and general 'worry'.
The world is a very different place and there is no one size fits all approach.