When AI token costs go near zero
Training AI models was never cheap. It requires a lot of energy. And it is usually spent in a very inefficient way. For example: computers can calculate things faster, by doing everything in binary. But if you ask any AI model about some computations in binary or hexadecimal, then they will convert everything to decimal first, then compute it in decimal, and then convert it back. And all of that while doing many mistakes in all conversions between different bases.
and AI robots make products like pancakes
The quality of such products is quite low in practice. They seem to work, if you look at them the first time, but the more you dig into the details, the more broken it turns out to be.
And then, guess what: you have more work, instead of less. Because first, you have to fix AI mistakes, and then you have to do the job correctly, from scratch.
So, I am not worried about AI taking our jobs. Actually, they will give us more things to do, because we will have to fix their hallucinations first.
everything will become so cheap
I don't think so. Even now, there are places, where "using no AI tools" is considered as an advantage. If anything, it will make things more expensive. First, because it will be needed to cover losses from investing in AI, and second, because correcting someone's work is more expensive, than doing it correctly from scratch, if you know, how things should be done.
inflation will become a thing of the past
It won't be, because inflation is a tax, that is invisible, and can equally affect everyone. If governments will stop inflating their currencies, then they will lose control over it. Producing coins out of thin air is needed, to hide their problems with more money. If they will stop doing that, then some problems will arise, and they will lose their power, if people will be too disappointed.
So, if they have a choice, to use inflation, or announce bankruptcy, then they will always choose inflation.
what would global deflantion do to Bitcoin?
If fiat currencies would have deflation, then Bitcoin wouldn't exist. See the message in the Genesis Block: "Chancellor on brink of second bailout for banks".
As long as there will be some "bailout for banks", Bitcoin will be needed.