Have you been to the Hollywood Theater in Portland? They have a 70mm film projector something no Cinemark has. You can see movies like Dunkirk in the format the director intended.
Of course, I saw Dunkirk in IMAX 70mm projection at the Metreon in San Francisco, which is a state of the art screening room, but that will probably only ever happen every few years. Sadly the Metreon recently remodeled with completely terrible seats (only in the IMAX room), so I'm rarely tempted to go there.
More importantly, though, not very many movies were/are shot in that format. Not enough to really build a business on.