How horribly American.
Bill may earn 1000 more than you do and can sack you on a whim but unlike in, say, Germany where you have less wage disparity and greater job security you don't have to address him by his title, nor he, you.
In any case, these subtleties—not that they're all that subtle—are lost in internet comment land.
Military, law enforcement, medical, and educational institutions still reinforce the ideas of titular address, but its fallen by the wayside in many places.
In my 20 year career, I've worked in all sorts of industries across corporate America including NY finance, insurance, politics, and medical and educational institutions as you list. I've never been in an environment where people addressed even the CEO as "Mr. xxxx."
My last job was at a research hospital. Being old school, I always start introductions by addressing researchers and doctors as, "Dr. xxxx." Everyone insisted I call them by their first names, and a few outright told me they felt uncomfortable with me addressing them as "Dr. xxxx." One said, "Only psychopaths address people by their titles."
I can see how titles still holds true for military and law enforcement, but I've never seen an institution where that even exists today. Probably because it's a huge red flag of insecurity if the head person requires it.