There are enthusiasts and early adopters using this in small businesses already. In terms of "practical niche" the use case I've seen so far is "n8n but you create workflows by talking to it" aka business glue to automate idiosyncratic things.
I think HN being mostly quite technical under estimate the latent demand for ad-hoc business automation by people who know what they want to happen but aren't comfortable writing code.
You could look at it as a generic replacement for many types of AI SaaS harness. Previously if you wanted to reduce the workload of an office worker say reading work orders (that arrive in 50 different formats via email, sometimes as pdfs or behind portal links) and entering them into job control, you would need to write a custom agent harness or use a SaaS. Now you can sort of "mold" this thing like clay and get it to do the job. Instead of writing an API integration for the job control system you can just give it the openapi spec. Instead of writing your business logic in code, you can describe it in English. If you are technical, you can work with it to turn parts of the workflow into code to reduce token spend or make them more deterministic.
Naturally, it has all the disadvantages of home built automation (typically limited reproducibility, less secure, not generalised).
There's a lot of jank and risk but, hiring people can be pretty hit and miss in that regard also so for small businesses it's not as "out of distribution" as you might think.
Corporate is a different story.