Who knows, if the viewers like the sound of what they hear posted online by a particular local dealer, they might want to check it out in person for themselves.
Great point, which is why some go to great lengths to ensure the best possible recording they can. There are even some reviewers who advise to wear a set of good headphones since they record and playback binaurally.
Granted, it's not the same as streaming but it's not as low-fi as some would have you believe.
All the best,
Nonoise