What are you going to use them for?
Consumer batteries are already good enough IMO. Cheaper batteries in large quantities are what we need more of.
Any kind of consumer power technology can only ever be truly "good enough" if it never causes any inconvenience or significant cost.
For almost all devices there is no good reason to care that the nominal voltage of NiMH rechargeable batteries 0.2V lower than the nominal voltage of alkaline non-rechargeable batteries. Alkaline batteries have a steeper initial discharge curve and pretty quickly drop below 1.3V.
If your device has trouble with 1.3V it is either going to almost instantly stop working if it is a high load device, stop working after using maybe 10% of the battery's capacity of it is medium load, and maybe 30% for a light load.
On the lasting a decade or more front, I'm still using 19 of the 24 1st generation Eneloops I bought sometime before March. 2 died and 3 are missing. Last time I went through and measured their capacities, about 3 years ago, they averaged 1886 mAh. They were sold as having an average 2000 mAh capacity with a minimum of 1900 mAh.
I've also got 15 4th generation Eneloops bought 2014-08. Those are also all still fine, with an average capacity of 1960 mAh.
You might wonder why I bought the 4th generation ones since the 1st were still fine. It is because they greatly improved the self-discharge. 1st generation was specced at retaining 80% charge after a year. 4th generation is specced at retaining 90/80/75/70 after 1/3/5/10 years. I've got some lower power applications where changing batteries is annoying, so I want to minimize self-discharge.
[1] https://www.nytimes.com/wirecutter/reviews/best-rechargeable...
The few times I've measured the voltage of my non-rechargeable AA batteries (which, granted, was infrequently, and not recently), I haven't seen them drop below 1.3V until they've been in use a while.
And I've much more reliably observed that when I try to use rechargeables in my electric toothbrushes (Oral-B Pro Clean, the kind with separately moving round and long brush sections, which are, alas, no longer available anywhere I've been able to find), they start out very sluggish, and gradually descend to near-uselessness, while using non-rechargeables makes the toothbrush very energetic at the start, declining fairly steadily over a month or three, with it matching the level of the rechargeable at something like 2/3 of the way down.
I'll take a look at the Wirecutter link; thanks!
I mean, that's not the case with current consumer power technology
