Hi,
I don't think so. Progress has been made in the last 10 years but many of the older lenses are still pretty OK. Performance at large aperture may stink a bit, however.
On the other hand, Canon and Nikon produce some really good lenses, AFAIK, and so does Sigma. Some of the new FE mount lenses may be stellar according to reviews, like the 16-5/4, the 90/2.8 Macro, the 35/1.4 and also the 28/2. Personally, my two new lenses for A77rII I have on order are the Canon 24/3.5 TSE and the Batis 85/1.8.
BTW, Zeiss is definitively saying the 24-70/2.8 ZA is good enough for 50 MP. Personally, I cannot tell as I don't have a 50 MP camera. But, my guess is that it depends…
Many older Zeiss lenses have a huge sweet spot but not really good corners. Just to take an example. Comparing my Zeiss Distagon 50/4 FLE on the P45+ with my Sony 24-70/2.8 ZA the Zeiss/P45+ is very sharp in the centre but the Sony zoom on the Sony Alpha 99 SLT outperforms it easily on the edges. Corners? I don't know!
Real world is a bit complex, it is not like there is a single truth. Some lenses have a large sweet spot and weak corners. That may have been quite typical of older lenses by Zeiss. Newer designs utilise new technologies like AD glass and moulded aspherics and may perform more uniformly over the field.
Best regards
Erik
That still doesn't give them the ability to make lenses precise enough for today's high-resolution sensors. Minolta's lenses from 10-20 years ago may have been sharp enough for the cameras of the day, but fall down flat compared with modern lenses in front of a 36MP sensor (or a 24MP crop sensor).
The E-mount 16-35, 24-70 and 70-200 aren't particularly great optically, with a general lack of corner sharpness and the 24-70 showing significant distortion. Sure, they'll do the job, but I'd much rather put a razor-sharp Canon, Nikon or other lens in front of the camera.