It will be interesting see if the next waves of wifi products solve this. For Wifi 6 and Halow there's a new feature called 'target wake time' that will let these devices sleep (and not pollute spectrum) for longer.

Wifi 6 also brings OFDMA which will let stations use much less of the channel at a time (instead of a 20MHZ+ chunk they can just use 2MHZ while other stations use the rest). 2.4GHz being stuck on old Wifi 4 (or worse) devices hasn't helped the situation.