Easily resolved...
Dongle A: HDMI audio extractor to split off the digital audio into an analog signal.
Dongle B: Analog audio splitter (2 way, 3 way, whatever you need- however many sets of earphones you want to be able to listen at the same time).
Dongle C: Analog to Bluetooth Transmitter (one for each set of BT headphones you want to be able to use at the same time).
Of course this is taking that "pure" digital signal, converting it to analog, then something else is converting it to (BT) digital again, but us "digital is better" people can just pretend like that's not happening.
So, let's say someone wants to play to both themselves and a spouse. 1 Dongle A, 1 Dongle B that splits into 2 cables and 2 Dongle Cs (assuming BOTH people have BT headphones/buds).
Yes depending on your situation, by this point, you may have spent more on dongles than you did on the
TV.
Bonus: Dongle B and Dongle(s) C can go traveling with you too to bring similar functionality to mobile devices. To cover all bases, be sure to bring the Lightning to Headphone jack dongle into which Dongle B can plug... as well as Dongle D+ options in case the cute person in the seat next to you with whom you wish to share some audio happens to have wired headphones but no BT ones with them. Then, you need dongles for USB3C and Lightning-terminated wired phones/buds for them... OR you might opt to bring along an extra pair of BT ones to share with that near-stranger... OR you can just say "sorry, I can't share my audio with you because, between the 2 of us, we do not have the necessary combination of dongles to make a sharable connection possible."
Welcome to "the future" of audio. Apparently, it's a kind-of mobile Radio Shack future: dongles for all seasons.
Update: but it's all worth it while we eventually transition to USB3C (probably still many years from now) right? And then there's
this article to show what fun "the future" of wired really is.
"What happens when you fragment away from a very-long-term, very-well-established 'just works'
with everything standard for $800, Alex."