Every midjourney image has the same feeling to it. A bit 1950s sci-fi artist. I guess it's just that it all looks airbrushed? I can't put my finger on it.
Anyone can get a camera phone, take a picture and use some free software (e.g. gimp) to get great results in post-processing.
Most non-expert users though want to click on a few pre-defined filters, find one they like & run with it, rather than having more control yet poorer results (precisely because they _aren't_ experts).
If Midjourney applies this to all their artwork then maybe it alleviates some of the ethical concerns (Midjourney then has a "style" independent of the training data)