even though i ve read that with ETOPS 207 min. you can make any distance or route on earth, so why is it.....?

Question

...not allowed to travel some specific routes with 2 engines?

Answer 1

There could be several reasons. Most airlines don't fly in areas of "magnetic unreliability" i.e., the polar routes, even though they have the range. Companies prefer an extra margin of safety. Think about it, 207 minutes is 3 hours and 33 minutes. At 550 MPH, that's almost 1900 miles. Do you want to have to travel 1900 miles on one engine? I wouldn't.

Answer 2

It is interesting that the change to ETOPS 207 was based on the proven reliability of twin engine aircraft which are now becoming old. Generally twenty year old mechanical devices are less reliable than new ones. I like four engine jets for trans oceanic flights.