other than BTC being a more flexible asset than USD and not mainly tied to one geographical area

I wouldn't say it's tied to a geographical area, but more that bitcoin can be an alternative for the unbanked, and there are many of them. Although, many non crypto-specific financial services started to pop up that only need a phone.

Adjusting to a deflationary world will be hard for the most part, is the debasement trade still valid too in a deflationary world?

The opposite would be true in a deflationary economy. The value of fiat would increase over time instead of slowly going to zero. But imagine what that would mean to the economy: prices going down in dollars (because of a stronger dollar) means less profits for businesses that have costs in USD, thus economic contraction.