In my experience very few film era lenses are capable of fully resolving the potential of modern sensors, so I restrict them to film camera use, except for video.
Well, you'd be wrong.
I hate film lens adapting, for a variety of reasons, but the lenses are very much on par, or better in some instances than modern lenses.
The priorities are often different. Ultimate mid sharpness are often chosen over corner sharp. Contrast and colour is often prioritized over slight apparitions and tangential coma.
But most importantly approximating telecentric projection is not as much of an issue with film lenses.
At most you are going to suffer a bit of vignetting and anisotropic smearing.
With a sensor things are much worse, if the light doesn't hit the sensor at close to a right angle.
135 film has much higher resolution than most scanners will let you see, some film types, higher then any equivalent size electronic sensor.
Lens testers back in the day would study film under a microscope, do big prints when testing, and use electronic sensors when testing lenses.
Their ability to judge resolution was probably as good as what we have today.
Any lens better than the competition, on the usual parameters, would win in the sales race, and vice versa.
Which is to say, the race was always on, and there is a real limit to what you can economically and practically squeeze out of a 35x24 projection.
There will always be monstrosities like the Otus lenses. But those will never be practical in any sense of the word.