I can give a basic example of why chat-based UI will not dominate.

Let's say I want to change a setting that uses a traditional radio button UI:

- Autoscale servers - Manual scale servers

It's much easier to discover, understand the options, and make a decision via a radio button UI than to ask for my options via chat. That would look like:

"I'm having load issues on my servers. Can you increase the server capacity?" "Sure! Do you want to autoscale or manual scale?" "What's the difference? Are those the only two options or are there more?" "There are only these 2 options. The difference is..."

That's just a worse UX.