I think its pretty remarkable that bands like Husker Du and Meat Puppets recorded albums on the extreme cheap, with no production budgets, no label promotion, nothing, and they're still relevant, discussed and beloved 30 years later. That is significant.
I agree that Adele is talented and her records will be listened to in the future, but you cannot compare her 'art' to bands that made music entirely on their own, without a legion of handlers and writers and promo people, that is still cherished by a significant number of people.