The problem IMO is simpler.
You have a product, which sits between your users and what your users want. That product has an UI for users to operate. Many (most, I imagine) users would prefer to hire an assistant to operate that UI for them, since UI is not the actual value your service provides. Now, s/assistant/AI agent/ and you can see that your product turns into a tool call.
So the simpler problem is that your product now becomes merely a tool call for AI agents. That's what users want. Many SaaS companies won't like that, because it removes their advertising channel and commoditizes their product.
It's the same reason why API access to SaaS is usually restricted or not available for the users except biggest customers. LLMs defeat that by turning the entire human experience into an API, without explicit coding.
Hmm. I think none of what you wrote is applicable to my specific SaaS.
> Many (most, I imagine) users would prefer to hire an assistant to operate that UI for them, since UI is not the actual value your service provides
That's ridiculous. A good ui will improve on assistant in every way.
Do assistants have some use? Sure—querying.
> So the simpler problem is that your product now becomes merely a tool call for AI agents. That's what users want.
This is a big assumption, and not one I've seen in product testing. Open-ended human language is not a good interface for highly detailed technical work, at least not with the current state of LLMs.
> It's the same reason why API access to SaaS is usually restricted or not available for the users except biggest customers.
I don't... think this is true? Of the top of my head, aside from cloud providers like AWS/GCP/Azure which obviously provide APIs: Salesforce, Hubspot, Jira all provide APIs either alongside basic plans or as a small upsell. Certainly not just for the biggest customers. You're probably thinking of social media where Twitter/Reddit/FB/etc don't really give API access, but those aren't really B2B SaaS products.