in the 90-ies anyone could easily prototype with tools like Access (and all the other "4GL" tools which were similarly all the rage back then). That still didn't preclude companies from buying their major software from software vendors instead of doing it themselves.

In some sense having customer able to prototype what they want is a good thing. I did it myself as i was at the time on that side, and having a quick-whip-it tool was a good thing to quickly get some feature that was missing in the major software before that major software would add it (if at all). (And if one remembers for example Crystal Reports - while for "reports", it and the likes were in many senses such quick-whip-it tools for a lot of such customization that was doable by the customer.)

So, after initial aftershock - "Ahhhh, we don't need software companies anymore!" - we'll get to the state with software companies still doing their thing just with a lot of AI as specialization is one of the main thing in modern economy and AI becomes most powerful tools of the trade. (and various AI components themselves will be part of software delivery, like say a very fine-tuned model (hosted or on-premise) specific to the customer and software - Clippy on steroids)

(Of course some companies wouldn't survive the transition just like some companies didn't survive the transitions to client/server, cloud, etc. while some new companies will emerge like Anthropic has today or Borland had at the time)