Never did SPARC assembly, but ISTR their registers were basically a ring of groups of registers allowing fast context switches as long as the call depth stayed shallow (fsvo shallow). When the ring was exhausted, you had to stash away in memory.
EU isn’t equivalent to the states (yet). It’s a loose’ish unions of nations. Passports are nation-issued, as are most professional credentials, but everything is recognised intra-union. In US (and Australia), passports are issued centrally, states are more like a local subdivision, irrelevant abroad.
US driving licenses are admittedly state issued. I suspect it’s more about violation points than anything else. And there’s a drive towards a federal format there as well.
(Sorry if I’m simplifying here.)
I had a Swedish (I’m not swedish, but my first EU style license was issued there) license in NYC and had it renewed through the consulate with laughable little hassle. When I moved to UK (pre-Brexit), again, the swap was smooth. I religiously believe that when I move back to EU, I’ll be able to get an EU license back (unless I hit an age trigger). I actually think the current EU license is awesome. I don’t dispute the underlying criteria for issuing could be improved, but post-issue, it’s pretty great today.
As I read it, at least the physical license will remain issued by member states. It’s a standardisation of license rules and an app (which is probably offered by EU).
(Personally, I’m not sure this is all that important in light of the problems EU is otherwise faced with, and I really hope licenses will remain a national document – recall when Brexit Britain under Johnson didn’t recognise EU in a diplomatic role since it isn’t a “country” – but so be it.)
Using NATO infrastructure would presumably invite US to the table, which is probably not desirable, even today.
The fact that x86. Hasn’t changed its foundation much, isn’t that just a combination of hardware making up for original design shortcomings, while economy keeping better solutions at bay? (Not a chip guy, I’m likely wrong.)