If the price goes up ( for foreseeable ever ) why would I spend my #sats ? If I don't , then no ancillary infrastructure (like plastic cards and swipe machines ) would be built and mass adopted ..

It becomes cash ..only if corporate like Strategy ( or #SBRs) fix the price of #bitcoin at say 10 K .. which they can do very easily .. eg - start selling if the price goes above 10 k and start buying if it goes down ..