I could not agree more emphatically with your points on CRTs, OLEDs, etc. So I hope you won't mind me quibbling on one statement.
> Consider film grain - it's an artifact, an unintentional or unwanted side-effect of how films used to be made.
I don't think it's quite so binary. Depending on the context and intent, film grain can be an undesirable artifact of limited celluloid chemistry, optics and available light. But it can also be an expressive aspect of the artistic medium no different than depth of field, focal length, color timing, grading, etc.
There are certainly examples of low light scenes where it's clear the filmmaker reached the limits of then-available optics and chemistry and they were forced into compromises such using higher-speed film and/or 'pushing' the chemistry during film processing. These can increase grain and the result is often shadow detail being lost in the noise floor. I agree that's always bad.
But there are also wonderful examples where directors and DPs very intentionally selected film stocks for their unique texture, gamma curve, color sensitivity, etc as an expressive choice. In those cases, it's no different than a painter intentionally using different canvas textures, brush bristles and pigment viscosity as part of their expressive palatte. In this form, the unique textures of different film stocks are often referred to as 'image structure' (a less pejorative term than 'grain' which is often construed negatively).
> But because it was a part of a production, people wanted it back
Artists hate any limitations on their vision, whether technical, financial or societal. They want maximum expressive freedom yet also grudingly concede pushing against limitations often elevates their work to new heights. When film grain was a limitation they struggled against, they hated it. When grain is an artistic element giving their image texture, they want in their toolbox.
To be clear, not all chemical, optical or technical limitations from the past were expressively useful. No VFX artists are pining for the black matte outlines from misregistered optical printing or generational mismatch in multi-pass composites. :-) Interestingly, as optics, lighting instruments and film sensitivity improved in the late B&W era, it was briefly trendy among some cinematographers to abandon depth of field as an unfortunate historical limitation of the past. Of course, it was just an over-reaction to a long-resented limitation finally becoming a choice and DoF remained an invaluable storytelling tool in the hands of a master (https://creativecow.net/depth-of-field-gregg-toland-citizen-...). I just want to avoid similarly over-reacting by dismissing the creative value of image structure and texture as we leave unwanted graininess in the past.
I suspect we'd have several enjoyable beers debating edge cases; which visual artifacts of past technical limitations can arguably have expressive utility to visual storytellers going forward and which have no real redeeming qualities outside retro callbacks and nostalgia? I'll nominate anamophic lens flares to start: https://theasc.com/article/star-trek-into-darkness/. My take: J.J. went overboard intentionally milking them in ST:ID but I'd be horrified if Spielberg digitally removed them from Close Encounters. Philosophically, I think the same principles broadly apply to retro gaming and preservation. So much so I built a custom arcade emulation cabinet around a 27" Wells-Gardner 9200 quad-sync analog RGB CRT and Radeon R9 380x. To me, it's about authentically preserving original artistic intent, especially when the original creators placed individual pixels by hand specifically to leverage certain analog video artifacts.