It's kind of amazing that you're clever enough to generate a complete decision tree for all the problems and solutions, and yet still have a blind spot for what the problem is, despite six people trying to explain it.
They are all things like "oh I have to ride in my friends car who has a 3.5mm input jack but doesn't have bluetooth input and also only has the cable without an adapter".
There's another comment about how the latency on bluetooth is bad, and this is a problem because they are a music producer who presumably produces on their mobile phone. Again, it's such a small subset and the fact it is solved perfectly with a $10 adapter makes me think the complaints are way overblown.