Standard batteries are pretty great as you can just swap them out if you need the device charged now and they don't necessarily add to trash either as you can easily buy rechargeable batteries, hell there are even now AA batteries with usb plugs you can charge on an usb charger.
The lifetime of your device is also not limited by the internal battery cell which might or might not replaceable at all (an operation which might range from "relatively easy" to "impossible without destroying the device" - not even considering sourcing a fitting cell which might be impossible) and *will* eventually wear down, as you can just buy new batteries. It's just stupid all around. A bit ago I was looking at getting some wireless devices (mice, keyboard etc.) and idiots on youtube actually critizised the devices that used standard batteries, calling it "outdated", as it usually is with these youtube knobs, without explaining why they see it that way. Pains me to say, but internal batteries that are charged via USB might actually be something many customers want.