In the theater I worked at, film was typically poor because: Cheap $100 lenses, cheap Chinese bulbs, poor, never cleaned parabolics, a policy of "fix it when it breaks, screw regular maintenance."
Basically DLP is new so the they are in better shape. I have already been to theaters where the green was no longer aligned with the red and blue. (Mirror was out of alignment somehow...)
Basically film will look better if you have identical conditions and the projectionist gives a crap about the presentation. 35MM still has a wider color range and higher "resolution" than even 4K DLP. The problem tends to be finding someone who cares, uses things like nice Osram bulbs [better color range, and brighter per watt], cleans the gear, aims the optics properly, uses quality lenses, keeps the traps maintained etc.
I used to take pride in my work. However you could tell when they built the building the theater company didn't care because the projection windows were not even aligned with the screens making it impossible to align the optics and square the image without distortion or very expensive trapezoidal correction lenses.
Mean while DLP allows you to cheat and adjust the alignments using the mirror arrays at the cost of some DPI / distortion.
OP, this is the definitive answer.
A good film experience requires :
A great print/copy on high quality film from the studio
Proper storage/delivery/unloading of said film at theatre
A good quality projector, bulb, lens, and proper maintenance/setup of said items
Good storage and treatment of the film during its run at the theatre
A good operator or operator(s), for the above two items to succeed
A good quality screen and no improper lighting (some theatres are horrible with ambient lighting that never turns off and can be quite detrimental to the experience)
etc, etc, etc.
Going digital takes most of those worries away with basically off-the-shelf stuff that is much less maintenance intensive, is easier to set up, and as the media material is digital you just don't have to worry about a poor 'print' or the issues that can arise with casual/unskilled/abusive treatment by underpaid operators.
Very high quality film experiences will be ever more rare as time goes by, the last two I can think of were both magnificent restorations, Lawrence of Arabia and Casablanca, both of which were shown in proper glory with care and excellent equipment at a local arts theatre.