Firstly, the rechargeable dont last as long in the toy. So if you have a ton of toys you need a lot of both AA and AAA because the toys will die more often.
Second, using AAA as an example, I can get non rechargeable for as low as 12 cents each right now. Rechargeable look to be 77 cents a piece if you can find them on sale.
Ive already looked into it for my family. We have rechargeable for things that make sense. I would need somewhere in the range of 150 to 200 rechargeable batteries and it would be a much bigger hastle. And guess what happens to those too? Recycled, because I would have no additional use for them beyond toys. And it turns out people dont like buying used batteries second hand.
I'm sure there are some people that actually do what you are suggesting, but saying that is the dumbest comment on Lemmy for stating what 99% of parents do is just silly.
So ive got 3 kids and a large extended family. My kids are the youngest so we are constantly being given toys second hand. Looks like at the moment, ive got almost 50 toys that take batteries in some form. Most take 2, some take 4. 200 is admittedly a high end exaggeration. But ive changes batteries in hundreds of re-homed toys at this point and I have never come across a single set of recharable batteries.
When my kids grow out of them, we usually give them to someone else, as they were given to us.