Raised beds can make gardening feasible where it otherwise wouldn’t be, like when all you have available is concrete slab or a driveway. They also just make gardening more feasible, period. Rather than plant in the native soil (or go through the work of amending it) you can plant in what is essentially a box of premium soil, and a more easily controlled environment. Working a raised bed is also a lot more comfortable than working one at ground level.
Rather than haul your kitchen waste to the curb so you can pay somebody else to haul it to the landfill, you can send a lot of it to a pile in your back yard that benefits your garden. But is the return you get from composting worth the work? It turns out the process is easy and requires very little from you outside of your normal household/yard care routine.