Running on standard replaceable batteries is definitely a feature and not an “outdated design”, especially when it comes to sustainability. And for some devices you can also have both replaceable batteries and charging ports (e.g. some cameras offer that). But yeah, I guess wireless Xbox controllers can’t be charged directly.

Having both, I strongly prefer being able to quickly swap in some new rechargeable double A's versus having to plug in a 15 ft cord from my system to my controller on the couch. I find the latter such a hassle that when my PlayStation controller dies I stop playing.