I concur. Building this control capability into GF wouldn't be rocket science. For simple folks like myself who almost exclusively navigate their SD cards by folder and then hit play on the track they want to play (with whatever follows following), the UI is straightforward (and MConnect nails it, when it's working reliably).
Where it gets messier, I'm guessing, is when people start wanting more creative solutions: playlists, shuffles, casting to, casting from, etc. etc.
In theory, by supporting these standard/open protocols Chord gets access to a broad ecosystem of app developers and other devices it wouldn't if it went proprietary. That said, IMHO the apps aren't up to snuff (and it hasn't changed much since Poly - this isn't a new lesson), so they're hitching their cart to a jalopy when they were hoping to have hitched it to a robust pickup truck. Not their fault that all the other apps are lame. But they probably should support a "painfully simplistic" solution within GoFifugre that bypasses all the bells and whistles BS.
Doody