I am 100% opposed to MQA. Not because of sound. It doesn't sound "bad" on my setup. Not because I'm a scientist who understands all the math. I'm not.
Instead, I oppose MQA because of the control they dream of imposing on the entire music ecosystem, with royalties and fees being paid to one company at every step of the way from production to packaging to delivery to playback, for no apparent benefit to anyone other than the one company.
Moreover, if they are successful in their schemes of world domination, decades of open, industry standard, cross-platform compatible, high quality music playback science is obsolete, taking away consumer choice. For what? A little blue light?
However, I am starting to be less concerned. So far, MQA adoption is limited to one streaming service and mostly one major record label. And that label still offers their files to every other outlet in industry-standard formats. Further, consumer access to MQA is limited to somewhere around 0.7% to 1% of the market, and we don't know how many of those actually use it or even care about it.
(By the way, if MQA is so superior, why don't Denon, Marantz, Yamaha, et. al. support it natively? Why didn't Amazon include it in their Music HD rollout?)
Anyway, this means that, after all these years, 99% of the market is unmoved by their claims of superiorty. This suggests that MQA is a massive failure, and isn't really worth worrying about any more. It appears they are a niche within a niche, and the market's natural antibodies are preventing it from going viral.