I don't understand why people sell Bitcoins for Inflated $Dollars?

Inflation is 8% now. Some say its much higher than this.

Bitcoin is deflationary so why people take risk of selling bitcoins for possible hyperinflated $dollars Jack Dorcey said?

If Fed don't raise interest rates high enough to tame inflation then inflations gets out of control right?

Why the DXY Dollar index is performing well in a high inflationary environment? Is it because the other fiat currencies compared to the dollar are much worse and more devalued than the $dollar?

If bitcoin goes to $100k next month and we sell at the top at $100k and 2 weeks later the $dollar collapses loses value then the sellers are screwed right? Can the collapse of the dollar cancel the bear market following the $100k top?