Series X controllers still work this way. Takes standard-ass AA batteries, including rechargeables; or you can buy a bespoke charge pack[1] which actually supports charging while in the controller.
[1] https://www.xbox.com/en-US/accessories/batteries-chargers/pl...
I really wish more devices went this way. In devices these days the thing that will fail first, long before other components, is usually the battery. It seems disingenuous of manufacturers to claim that rechargeable batteries are good for the environment and then ship devices without user replaceable battery packs.
> I really wish more devices went this way.
It's a shame Xbox Game Studios is run so badly, because pretty much everything else about Xbox is genuinely better & more consumer-friendly than what PlayStation & Nintendo are doing. But the main thing that matters is the games, and they just don't have 'em over at Xbox. Oh well.
And, if you use good quality 2500mAh rechargeable AAs, those controllers go forever between charges.