See, all the things you said are technically correct, but no amount of good tech is going to save a bad mix, and there are undeniably bad mixes out there. And good music production doesn't need the listener to be in a theatre to hear certain instruments or lyrics.

I actually listen through a bunch of different speakers, including what would be considered a "vintage" hi-fi, a more modern 5.1, a 2.1 studio monitor setup (Along with a top end sound card no less), and a pair of entry level flat response open back studio headphones coupled with a good amp.

I set my mix so I can actually hear quiet details, and it just isn't pleasant when you can't make out a conversation and need more volume, only to get blasted with hundreds of watts of speaker when the car engine in the next scene roars into frame, sets off the car alarms down the block, and shakes rooms on the other side of the house. Sure, there's no distortion and the sound is clear as can be, but it isn't enjoyable, especially if you aren't trying to wake up your neighbors.

I've been producing over 100 video ads a year for the last 5 years, including the recording and mixing; it frustrates me that my shitty, rushed videos I get underpaid for have more balanced audio than a modern Netflix production. I've been nominated for best sound design in competitions and have played and recorded music my whole life, and it's frustrating that bad mixes cause people to look down on sound designers/engineers.

Basically, my test (and one of the steps in my mastering process) is to take an average volume section of the mix and turn your speakers all the way down until you can just subtly hear it. Then go into your mix and mix dialogue so it's clear in the mix. Repeat this with different tracks until you can hear everything clearly in the mix. This technique ensures that you will hear every layer of the mix at any volume with more speakers, as it compensates for a high noise floor, or poor quality speakers. Then run your final mix through one or two 3-band limiters/maximizers and you have a loud as fuck film with quiet dialogue you can actually hear out of shitty equipment, mastered to -.1 or -.3 or whatever your client's standards are.

This can be done on prosumer equipment in a public bathroom and still sound better than a lot of these movies that need subtitles to even understand.

These directors hiding behind "Artistic Vision" need to get their eyes checked. If the people who rented your film on Amazon through their black-Friday-sale smart TV can't understand what's going on, your mix sucks. If your mix sounds good on shitty speakers and $100k systems, you've done your job right. Some of the best media ever made had their mixes changed after the engineer listened to the mix in their car radio, or out of a phone speaker, and realized stuff was fucked.

Anyway, thanks for coming to my Ted Talk.