I have to imagine many do, it sucks since what the hell are their options. I would like to think that most doctors at least care somewhat. I can't imagine how they feel if they think someone truly needs something and insurance just says no.
I know my sister at one point was having some critical medication for her denied so the doctor just kept giving her sample packs.
I went through an issue with a medication for me and it was still never resolved.
In many cases that issue can be resolved through an appeals process. But this takes extra time for providers, and they don't get paid for that.
Insurers may also require step therapy. Try a cheaper treatment first, then if the patient fails to respond they will authorize a more expensive option.
I know my sister at one point was having some critical medication for her denied so the doctor just kept giving her sample packs.
I went through an issue with a medication for me and it was still never resolved.