The 402 response code in HTTP might be a useful thing to "hook up" to Lightning, which itself is useful because of the Bitcoin blockchain.
Having fast micropayments payments running on data requests is useful for a wide variety of cloud applications, including but not limited to data transfer costs and queries to machine learning models, all without the need for "users" on the systems being accessed.
The way I'd put it is that the killer use case for Bitcoin is yet to come, which doesn't make it a solution for nothing, but more like a solution before its time.
https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/402