"ChatGPT3 will blow every single piece of software in the world."

Do you mean, like ... orally gratify?

But seriously, I'm still waiting for the death of print newspapers and broadcast television that the Internet was supposed to bring about back in 1995.

Maybe take a calm, relaxing breath or two.

Even if "the chat will be everywhere" the systems that actually do the work of making airline reservations or whatever will still exist much as they have for decades.

What you're suggesting is not the death of systems but a new user interface (UI) ... that will exist alongside web-based GUIs and other UIs for a long, long time.

New capabilities -- even revolutionary new capabilities -- don't typically replace existing capabilities; they coexist, often for a quarter of a century or more.