I don't think it will replace SaaS but I do think it can replace the need for a lot of the consultant work that goes around configuring and integrating the SaaS. It will be much easier to have a spec that defines how things need to be configured and the machines can implement it (using the SaaS as tools). Frankly this is the most annoying part. It's not that the B2B stuff can't do whatever, it's that it never gets implemented in ways that aren't a pain in the ass because it's all handled by people who aren't actually using them.

I really don't think it's not going to become "these prompts are specs" and then you have processes of reviewing implementations. It's one thing when you have randos building stuff and they leave etc. Having stored prompts and managed code that uses tools is a different beast.