Why can't you use both latch and seat belt?
Why can't you use both latch and seat belt? This is because the two installation methods could put too much stress on the wrong part of the seat and cause breakage or incorrectly distributed crash force. Both methods could even give you the feel of a correctly installed seat when neither system is properly tightened. This, of course, isn't safe.
Why do flight attendants get better seat belts?
In conclusion, flight attendants and pilots' seatbelts differ from those of passengers because of safety reasons. Flight attendants require the four points of the harness to hold themselves in place as their seats are often backward facing.