I'm not sure how forcing people onto a single currency and making it impossible for countries to control their own currency on a national level is inherently beneficial.

Let's be honest, the people who want BTC to be a single global currency want that to be the case because they feel they are "early" and will massively profit from that happening. Pretending it matters to poor people living paycheck to paycheck for whom money is ephemeral is top tier cringe.