Most luggage damage happens on the carousel and most luggage loss happens between two airports. This range covers both.
Straps keep a case shut if a zip fails and make a black suitcase identifiable from ten metres. Wheel covers take the abrasion that destroys spinner wheels on rough terminal floors. Trackers tell you whether your bag made the connection before the airline does.
None of it is expensive and all of it is the kind of thing you only buy after the trip where you needed it.