Not to mention their weight - the one I got is 30” diagonal and weighs almost 9kgs!! So that eats into 10kgs of the basic 20kg baggage allowance then if you add typically 14kgs of Scuba gear + 7kgs of clothing you have another 11 kgs left so you end up paying for the 15kg bracket of excess baggage fees … moreover the weight of camera electronics and batteries basically consumes most of my carry-on baggage so no option to stuff clothing in the cabin bag.
My pelican style case lies permanently below my bed frame as a long term storage box for my scuba gear.