Absolutely agree, but have to add a small nitpick:
50mm primes used to be lightweight. The trend is towards Sigma Art / Zeiss Milvus/Otus dimensions, and that means much better edge sharpness but ~1kg in weight.
50mm primes used to be lightweight. The trend is towards Sigma Art / Zeiss Milvus/Otus dimensions, and that means much better edge sharpness but ~1kg in weight.
Besides perhaps the Canon 50mm f/1.8, 50mm lens are big now. Like a grapefruit on the front of your camera, to the extent it kinda obviates the size reduction in mirrorless bodies—slimmer body, and a giant lens.
There are reasons for that. If you’re buying an interchangeable lens camera, you are probably after image quality, and the new generation of lenses are phenomenal. I am not sure if you’d call this Nikon cheap, but it blows away all their previous offerings. (https://www.zsystemuser.com/z-mount-lenses/nikkor-lenses/nik...)
Take Sony for example. They have their large 50 1.2 and 1.4, but they also have several small lenses: the insane 55 1.8, the 1.8, the 2.5G, and the 2.8 macro.
And you can go smaller still if you go the manual focus only route, e.g. the even more impressive CV 50 f2 APO.
But indeed, as the sensor resolution of 35mm cameras exceeds many classic medium format cameras, the best lenses have grown accordingly to serve that resolution. To me, the Leica M system stayed mostly true to the 35mm cameras of the film age. The other alternative in my eyes is mFT which offers great "digital" lenses in the size of small classic 35mm lenses.
Sony has been keeping the mirrorless full-frame lenses quite small. The old Sony 55mm f1.8 (which I count to be in the class of 50 mms) is still sensibly sized (less than 300 grams) although a bit prone to flares but otherwise quite close to Otus class sharpness.
And then there's the Sony's 50mm F1.2 GM halo product which is still less than 800 grams. It seems that they are pushing down the weight at the same time they are improving the image quality.
Sigma's lenses are a lot of cheaper than Sony's GM lenses but they are bigger and heavier in many cases and in some cases they are still are old designs for DSLRs.