Am I wrong to think that the answer is obvious? I mean, who wants web apps to behave differently every time you interact with them?
For a typical user today’s software isn’t particularly deterministic. Auto updates mean your software is constantly changing under you.
LLMs being inherently non-deterministic means using this technology as the foundation of your UI will mean your UI is also non-deterministic. The changes that stem from that are NOT from any active participation of the authors/providers.
This opens a can of worms where there will always be a potential for the LLM to spit out extremely undesirable changes without anyone knowing. Maybe your bank app one day doesn't let you access your money. This is a danger inherent and fundamental to LLMs.