A Pi has to add on other purposes and is not built specifically to be a stinkin’ phone AND a camera+. I power mine with a filtered iPower Elite. You are free to show actual stats that it is inferior to a battery. Saying it does not make it so.
The best sounding streamers I have are all based on RasPi. (All better than my first, a BluNode.) RP tech is just a shortcut to sufficient processing power for a network player. Then design tech takes over to make them sound superior. I refuse to operate a "streamer" that cannot play local files including HiRez and DSD.