Hard cases are particularly suitable when transporting delicate equipment or to prevent items from shifting during transport and causing damage to themselves or nearby objects. Hard cases are very common, especially among audio and lighting services that need to set up, dismantle, and transport numerous pieces of equipment daily, but also among meticulous musicians who have to carry a lot of gear!
Flight Cases, Cases, and Bags are widespread in environments like the music industry, both because the profession requires constant travel, and because the materials being transported are often quite expensive and can easily be damaged by impacts and bumps. For this reason, there are protections and bags designed for a wide variety of items. Moreover, if you're thinking of building your own hard case, it's also possible to purchase accessories like handles, closures, and wheels.
Returning to the topic of bags, in addition to musical instruments, it's possible to carry speakers and sound systems, lights, lighting effects, mixers, microphones, pedalboards, launch pads... in short, as you might have guessed, a bit of everything. You can often opt for soft, semi-rigid, or rigid solutions to ensure the highest level of safety.