Indeed. And for a very long time, D&D did indeed cater to them. With 5e the model has shifted significantly - sell fewer different items, but sell way more copies of each. Overall, that's working well for them.well... in some business models, there is such a thing known as the whale - the few individuals buying the majority of the products. Those whales are worth listening to, because they are they one buying!
In D&D, those are often the DMs...
In the new model, Whales are catered to with DM's Guild, and especially with those ultra-deluxe boxed set versions that G&B put out.