I mean I can’t really blame them for being smaller, the USB port is a lot of value added but is also pretty huge.

They make USB rechargeable lithium ion batteries in every common form factor. I use lithium rechargeable AAA batteries in my mouse and they work great. You don’t even need a charger, they are USB-C. Highly recommend.

It’s been done a lot, but its kinda pointless as any noise improvements from the shape are obliterated by the bad surface finish.