Answer:
These catalogs lack dimensional depth AND simple sense of size — much less the incredible lack of subtlety and accuracy in digital colors — which vary based on the type of monitor viewed on AND the settings.
The harm? They reduce art appreciation to that narrow portion of work which photographs well (say Dali’s “time” surrealism which is tiny but always looks big) and eliminates much of the best work.
I’d seen, for example, photos of Chuck Close work and always dismissed it for being digitized. And then I saw it in person and found it incredible — because everything that makes it incredible disappeared in those photos.