Oracle (READ: aggregated/decentralized APIs feed) services and other infrastructure that supports decentralized protocols (network graph, etc.)
Decentralized lending, borrowing, trading.
SaaS products in on-chain analytics, portfolio management, commerce aggreggation.
Gaming
Fine Art (a tiny minority of the art scene in crypto is pretty interesting, ex. distributed multiplayer run-time art, something that can't really exist outside of the medium)
Digital Collectibles as an end consumer product or in service of the construction of lifestyle brand / gaming / etc startups. (A lot of the most boring use cases land here, imo)
When I take a loan from a bank, I may use it for education, a vacation, medical emergency, a car or invest in a business which will generate revenue and employment.
What do people do with tokens they borrow in "DeFi"? Given that the tokens can't be used for paying college tuition or a hospital bills or rent or buying a machine?
On-chain financial stuff is just more speculation, and the vast majority of the gaming/art/collectible/advertising/content use cases are just stapling crypto onto something where it brings no benefit and often actually makes it worse.
There's a tiny sliver of cases where crypto brings real value by enabling something that you couldn't do without it (e.g. cryptokitties was genuinely novel and interesting). But it's just such a vanishingly small proportion of the ecosystem.
If you say, "Selling cryptocoins to others", that isn't actually a product or service.