Sometimes a 12volt tool looks good (lighter), but so far I don't have any. If I ever do I'll be comparing all the brands (and their catalog) to see which I think is best, already having Dewalt 20 volt tools gives them no advantage (My dewalt radio can take 12 or 20 volt batteries, but that isn't enough of an advantage)
I wonder if there's a market for battery adapter-shims? (then they'd start doing HP-ink-level shenanigans, if they're not already).
Looks like CharlesW answered my question before I asked it: https://news.ycombinator.com/item?id=41507481
https://tool-kit.co/wp-content/uploads/2021/07/power-tool-br...
Amazon has usually had the tool without a battery and charger but many more sellers had the tool with battery and charger and those were actually cheaper due to sale prices or due to the tool only not being Prime and having high shipping cost.
So I've ended up with the 3 batteries and 3 chargers for my 4 Black & Decker cordless tools. (It's only not one for one because the first purchase was a bundle of a string trimmer and hedge trimmer with one charger and battery).
I'll probably need to buy an oscillating multi-tool next summer and am thinking of going with something other than Black & Decker. That way the next time after that when I need a tool (probably a paint sprayer) my chances will be twice as good that I can find one unbundled that matches one of my existing battery systems.
Or you hold off on buying other tools because you want to be in a different battery/tool family.
There are convertors for batteries though, so I should probably consider that.