In lieu of an elected government and sane central bank, monetary policy will be controlled by a cartel of your locality's most powerful gangs and paramilitaries.
There's a reason the example quoted is always Star Trek and not Somalia.
It’s easy to get paid in BTC if you land a crypto job, but it’s the groceries part that I can’t really imagine yet.
So given the trilemma then, it sounds like Bitcoin maximalism means fixed exchange rates (since all countries use BTC), and free flow of capital (since that's the BTC ideal), which means no country can set independent monetary policy.
So you essentially have the Eurozone problems but across the entire world. Seems like many countries would try to avoid picking that side of the trilemma.
Usually a BTC maximalist means that within the context of crypto, they are BTC only and aggressively and passionately reject every other crypto token. This is what you call call a common maximalist stance.
Out of that group, a small minority is a believer in "hyperbitcoinization". This is an event where BTC becomes the dominant asset class, at the expense of gold, bonds, etc, with a market cap prediction for BTC ranging from 10-100T.
Even people with that (unlikely) hope, do not claim any currency replacement, only an asset shift.