Since October 2020, the entire future roadmap of Ethereum, the second largest cryptocurrency, has been heavily based on verifiable computation, in the form of rollups.
In 2023 alone, maybe 5 or so fully functional proving systems for running verifiable compute in the Ethereum Virtual Machine have been launched, and are currently live and operational. It's still early days, and there's a lot more work that needs to be done to fulfill the vision, but progress is happening faster than anyone expected.
How many actually do that and how many just make HTTP calls to SaaS providers? It only means anything if you run your own node and/or actually implement or at least use verifiable compute code.
I don't see why the difference matters. In both cases, verifiable computation is deployed and useful.
In the case of HTTP calls to SaaS providers, that's part of the promise of verifiable computation - that you can outsource it to a provider and verify that both the input and the computation are what you specified, and thus that you can trust the output. Even if its running in an otherwise black box on the SaaS provider's infrastructure.
Second line: No way. Very little of the cryptocurrency ecosystem and industry actually do verifiable compute in any meaningful sense.
A lot is API calls to third-party trusted services (who are probably doing that, yes).