On Sep 14, 2018, wrote
(in ):

Seems to me that FF is all about connectng back to the old 35 mm film
format, and very little else, since smaller sensors with the same
pixcel count in conjunction with shorter lenses could do the same
thing, BUT smaller and lighter. What part have I got wrong ?

Nothing!

For many years M43, and APS-C have exceeded the capability of 35mm film, as have
some of the small sensors found in the better performing Smart phones. However,
there are some characteristics of modern FF sensors such as DoF, and low light
performance which only a handful of APS-C sensors can come close to. In the end
many of the FF pundits have failed when it comes to discerning the source of a
well made print from FF, M43, APS-C, or even a late model iPhone or Android
phone.