I am sitting in a commercial studio today, working on a mix. I have been sitting here for most days over the past 8 years. This is my job.

The equipment in front of me in the control room alone is worth around 90000 (SSL board, RME conversion, Neumann kh410s for monitoring and serious acoustic treatment) — nothing super crazy when it comes to studio setups but certainly in the 'above average' area of things, even in this profession and certainly when it comes to anything normies are gonna experience. My most expensive headphones (I own around 10) are Sennheisers for ~1.5k, powered by a Phonitor, which cost around the same.

To toot my horn, I have been fairly successful at this. I work with chart pop/alt/indie musicians on a regular basis. I am actually in the rare position to have made a good living off of this.

While working on a Mix I am intensely focused on listening, to the point where I will not notice when being talked to. I am listening to and passing judgement on over 100 individual sources of audio running at the same time. I will hear if one of the 16 background vocals tracks is slightly out of tune. I will hear if there's an unpleasant resonance on a guitar somewhere for a split second. Absolutely nobody, including the artist, will ever be as acoustically intimate with the whole thing as I am during this time (this is probably true for any notable mix engineer).

Considering all this, the highly intensive and focused process, the considerable amount of money carefully spent (in contrast to audiophiles just throwing money at something because of what I would imagine are insecurities and boredom, I have to make a profit and thus spent my money carefully even) and my experience, I rank the difference between high quality cbr/vbr mp3 and lossless as so fucking negligible, that I will randomly chose either when making exports to compare my future working status to.

To elaborate on what this means: I will make an export, place it in the project, continue working on it, and then at a later point solo (= switch to) to those exports to check if I am going in the right direction, if I improved on the critical parts, if something got lost on the way.

To be absolutely clear on this: I would cost me an extra half second to make sure I always have a 24/96khz export of that mix as my reference instead of a maybe-i-dont-care mp3. I do not invest that half second. I don't know how to be any clearer than this.

Do not confuse this with me not being able to probably spot the difference. It's just that it is about a skill as spotting a difference between two apparently white walls. I am sure with enough effort and attention to the task anyone would be able to make their brain tune in on the the differences. But why the fuck would anyone do that? There is no upside. No, it will not make you a better music listener or the music more enjoyable. If anything you are doing more focusing on the wrong things.

Every now and then I stumble across this topic online and what used to be insecurity has turned into perplexion. I have no hope for or illusions about that the people who have trained their brains to search for mp3 artefacts (well done, I suppose) but maybe I can reassure some who seem to be on the fence on this topic: Do not dwell. This is a great way to waste time and money and get absolutely nothing of value in return. Aim for headphones you enjoy listening on. They are probably not that expensive. Make sure they have replacement parts available, specially for the ear pieces and cable.