Making lows mono doesn't sound better (although sometimes it can make the bass seem less muddy, but if you have muddy stereo bass you'd normally fix that too). Some of the highs and lows come back in the pressing. You cut more in the vinyl master only for them to be recovered somewhat in the pressing. You don't get it all back, so the effect I guess has an element of the unknown. Thought I'd just clarify that.
The distortion and chorusing are definitely aspects of 'warmth' too. So, it's not just about the highs and lows. Producers absolutely try to 'warm up' their digital sound sources, stems, and masters with harmonic distortion. I guess you'll always get a bit more with vinyl.
I think some of this is the culture of the industry itself. The major recording studios, engineers, etc. were on a 'war against distortion and noise' from the early 50s. Then digital came along and suddenly it was possible to have low-noise floors and pretty much zero distortion through digital sound sources (plugins).
Because digital was deemed to be 'cold', there has been a bit of a backlash against that in the past decade or so:
* Major mixing console manufacturers, like SSL, after decades of trying to make their mixers as clean as possible are now releasing desks like the Origin [1] which are throwbacks to their late 70s desks. Every classic compressor, EQ, delay, flanger, phaser... from the 50s onwards, still exists either in original form or cloned-form. People are still buying the equipment of the past to make music. And digital plugin manufacturers are stil releasing plugins that try to emulate the old gear.
* New genres appeared like 'lo-fi' [2] that actively does what you say. It tries to degrade the sound for digital too.
* The fact that vinyl isn't just still here, but resurgent, is I guess more evidence of that.
But I still think, to a certain extent, that professionals in the industry want to use the full range and accept that some of it will be lost with a vinyl press. Brighter music is perceived to be louder, so on a radio or something like that, it will cut through better and be more likely to be noticed. I think the recent end of the 'loudness wars' [3] may well see some changes toward releases with different EQ curves.
I own over 10,000 records. I don't buy them because they're 'warmer', I buy them for the UX! I have a terrible memory, but I remember the sleeve of every record I own. I don't know what they're called, just "it's the green one"! I think the warmth argument is slightly overplayed, but I also understand why subliminally people might feel that records are subjectively better because of it.
[1] https://solidstatelogic.com/products/origin
[2] https://www.masterclass.com/articles/what-is-lofi-explained
[3] https://en.wikipedia.org/wiki/Loudness_war