Labels tend to ask for "impressive" footage of the artist in question playing it live for promotion. Whereas this may not always be available, some get a bit creative. In a world full of well polished turds, sometimes you're better of joining team-bullshit than to stick with team-reality. This doesn't fit too well my my sense of integrity, yet marketing is what it is and sadly an inevitable part of getting yourself out there. Wish it wasn't.

It helps bring visual perspective to the track, but either way people are trying to get exposure for their music and there's only so many options to do that

This is how it is nowadays. Sometimes you play your own track in a set and you don't get the powerful fire/strobo/CO2 combo, but let's say it happens the track after. Sorry to tell you, but the reality is very brutal nowadays (if you didn't realize it earlier) - people mainly react to shiniest, most impressive visual things. They are surrounded only with funny, catchy and shiny stuff all day long, right? If you want to be that extremely realistic and then get 10x less views - it's up to you.

You don’t need a microphone attached to a camera to dub audio on a video.

Just sounds like marketing to me… not really that deep. Never gave it much thought, nor would I default to it as some kind of nefarious act. They want to promote their gigs and productions at the same time. Using an original audio source will also be a better experience for the end viewer than the live audio. From a copyright perspective they don’t have the rights to the audio if they were playing someone else’s work anyway. Sound too overly concerned here, and with others. Worse problems exist.