I think you're assuming that there's an issue with the macbook's implementation instead of the device you're pairing it with.
Like I had mentioned previously, if one side of the paired devices has a garbage antenna setup, it will have poor performance. Things like your soundbar, or a generic bluetooth speaker probably use reference designs for their BT setups and have not tuned them for the enclosure or use case.
not an assumption. given that everything else works together, it's the macbook pro that's the odd man out. my other devices include multiple bluetooth speakers, mice, phones (android and even windows phone), surface pro, iPad, and others. they all work seemlessly with bluetooth, but the macbook pro struggles with most, especially when trying to play audio over bluetooth. like i mentioned, this is a well-documented problem if you do even a basic search.
Like I had mentioned previously, if one side of the paired devices has a garbage antenna setup, it will have poor performance. Things like your soundbar, or a generic bluetooth speaker probably use reference designs for their BT setups and have not tuned them for the enclosure or use case.