I’ve watched 4k digital films at two exceptional digitally equipped theaters:

https://cinerama.com/Technology.aspx

https://www.geekwire.com/2015/photos-inside-one-of-the-world...

And I swear each time I’ve seen noticeable digital artifacts (usually where text or some long swoopy line is involved). The digital projection has never given me a “holy crap” hair standing on end visual response.

Not so with 70mm or 70mm IMAX (RIP Seattle’s equipment). I saw Interstellar in 70mm IMAX, and the space scenes really were stunning. Like, clearly amazing.

When we saw 2001 in 70mm at the Cinerama a few years back, several people in our group all remarked how the initial sunrise almost made you feel heat.

Yes, that could be my imagination. But I’ll add that I didn’t even know that I was watching The Master in 70mm a few years ago. I’d watched it with a friend, and I distinctly remember coming home and remarking to my wife how amazing the visual detail was.

I’m firmly in the “digital has yet to wow me visually the same as 70mm” camp. And I say this as someone who thinks CD was the most profound improvement in audio quality that I can remember in my life. So, I don’t think I’m just being nostalgic.

Digital (video) artefacts are definitely a thing. Unlike with the CD, where we got to a point where over an hour of essentially perfect quality stereo music fits on this cheap mass-produced object, digital cinema is in a place where they can do something that's very good - much better certainly than what you'd see in a second rate cinema after a picture has been out for a few months and the print has seen better days, but it's absolutely not perfect and I can well believe it's not going to impress anybody who can see a nice new 70mm print.

Basically every frame of a digital movie is a huge JPEG. That's not quite exactly what's happening, but it's close enough. So you don't have inter-frame compression artefacts, as you'd see on a DVD or Youtube video, but artefacts in the individual still images absolutely are present, albeit rarer because they're using a lot of bytes for each frame. And so yes, text would be especially likely to make this noticeable as it is in JPEG on web pages.