Probably the most reused amenity kit bags I’ve ever received were ones I got on BA back in 2015 that were meant to be repurposed as shoe bags… which I’ve been using them as since. (In fact, I am traveling right now and have my extra pair of shoes in one of them.)
Anyone who actually wants such a bag can drop $2 at Walmart. IMO that's preferable to airlines handing them out by the gazillion.