I would agree with your observations about the advantages of rechargeables vs. traditional throwaways.

My principal charging device is a Nitecore intellicharger i4 which will do NiMh AA, AAA, AAAA, and C, as well as a whole passel of li-ion sizes including 18650s, but not 21700s, in increasingly common offering. It gets power from the wall or also 12V cigarette lighters. I am happy with it.

I also hav some Fenix AAs with built-in chargers; they are powered with an integral micro-USB port. They offer the same in other sizes. The advantage here is that you only need a power bank and appropriate cable to recharge them.

I am currently focused on light weight, minimal rigs suitable for backpacking and isolated camping. Eventually I want to go big and have more juice to more effectively deal with the now common power outages (better than wild fires!).

As far as I am concerned, alkakines are obsolete Stone Age relics, although there is a place for disposable lithium batteries....