> The catch is that Li-Ion rechargeable batteries have much higher self-discharge rate than alkaline AA/AAAs, so you could not use them in remote controls anyway.

How does that compare with NiMh, or whichever is the current standard chemistry for rechargeable AA/AAAs? I may be misguided here, but I generally avoid regular single-use AA/AAAs, as it feels like a complete waste of energy - even if properly disposed of, I don't imagine they get recharged by some factory and put back on the market, so all the embodied energy that went into making them is lost.

> For powering iPhones, you can buy a few 18650 with a type-C/lightning case from AliExpress, but most people will prefer just buying a powerbank.

At least some of the power banks I've disassembled in the past were just 18650s with a case, USB port and charging circuitry, so I can't blame people for buying it already pre-assembled.

NiMh is better but alkaline still lasts longer. For low drain devices like remotes where shelf life is a bigger concern than power draw, I’ve heard zinc is better still. These are often labeled “heavy duty.”