What If The USPS Issued Some Stamps As Regional-Exclusives?

Yes the Providence Postmistress was/is a legend among collectors. She would go to great lengths to stock every postage item she couldget her hands on. There was another postmaster doing the same, I think in the Ca area. I think the USPS killed that in the end as far as I remember.

The biggest one in CA was probably Long Beach, The other major operations in the West were Tucson AZ and Salt Lake City UT (the latter ran into trouble with the rules).

Back to the original topic, I do not favor the proposed idea.

Several countries do (or did) issue regional-specific stamps - Japan's prefectural stamps, the UK's country definitives and Malaysia's state issues come to mind. As far as I know, in each of these cases the stamps are valid throughout their respective countries but are only sold in specific regions.

A very similar concept exists in currency with different coins for each country in the Eurozone.

USPS could certainly implement this idea if they deem it will benefit them - although whether or not this would create more hype around new issues is debatable.

Another U.S. example might be the early tagging experiments in the 1960s. I think there were quite a few stamps that were issued with tagging in some regions and without tagging in others. I wasn't around then, but it sounds like collectors who wanted both varieties didn't have too much trouble obtaining them(?).

I'd not mind regionals because this decade I already stopped getting all new issues, so what's a few more I don't obtain?

I doubt regionals would encourage people to develop more stamp friends. The present USPS refusal to sell singles already encourages that: "OK, you buy those issues, I'll buy these, then we'll swap half panes," etc.