Yes, I think that the old lenses by and large are not as sharp, but for some of these old lenses, the color and contrast and general rendition are very pleasing for certain shots. Modern lenses designed for digital have a slightly "clinical" look. Roger Cicala has a recent post on lensrental blog concerning the sensor UV/IR filter assembly. This is a glass filter on top of your sensor - thickness varies from 0.7mm to 4 mm, depending on the brand and type of camera. Most DSLRs have a filter thickness of 2.0mm +/- 0.5mm. This is likely taken into account when designing lenses for DSLRs. As it turns out, a difference of 2 mm does make some difference to resolution and contrast of some focal lengths at some apertures. What was the filter thickness of the film sensor? NO filter. So it is possible that the lenses were close to ideal FOR THE CAMERAS THEY WERE DESIGNED TO FIT. Note that one of the major problems of film cameras was to get the film exactly flat and on a predictable plane. There was always some small fraction of a millimeter variance with most cameras. A few large format backs were custom-built to have vacuum backs to hold film exactly flat - a real issue if you are shooting 8 x 10.
Of my collection of vintage (1970s - early 1980s)) prime lenses, none are uniformly sharp at f/1.2 - f/2, and the contrast also is weak, but one can still take a pleasing image, depending on your composition, lighting, and intention. (As I age, I see the virtues of imperfect lenses for portraiture). The AIS Nikkor 50mm f/1.2 has a hazy romantic look at f/1.2, is tack sharp at f/4, and for the time being occupies an honored place in my bag for landscape - I have even bought it a new fine screen (Eg-S) for my 6D. The sharpness of my other normal primes (Mamiya-Sekor 55 mm f/1.4 and Mamiya-Sekor 60mm f/2.8 1:1 macro preset) is good but not stellar by modern measures, the color is great though. I am learning my way around the AIS Nikkor 105mm f/2.5 currently. The best part of this is that these are "free", having been fished out from the back of the closet as an interim measure while I decided on full frame lenses to kit out the 6D.
Every serious shooter from the film days knew to avoid the 1970s - 1980s vintage zooms. S*cked.