Fewer guests are bringing their gear these days.
There are hefty baggage charges.
You also have the hassle factor of dragging around a large dive bag.
It makes sense to rent gear for casual diving.
If you have a mask, reg, and dive computer, do not leave them at home as these items are somewhat personal.
Nothing will make you madder than if you have your favorite mask at home, and all the ones you try on the boat don’t quite fit right. I have a large nose and a flat forehead (think neanderthal), so I know all about it.
If you are bringing regs and computers, do not check them as they have been known to not be in dive bags when they reach their destination.