I used to shoot with a Nikon D70s and a D300 and I didn't feel limited but all of a sudden with my Sony a7m2 the "small" PDAF area feels super limiting, even though I think nothing has changed.

Though the AF algorithm seems to have a hard time focusing to infinity at times... I'm saving my bucks for an a7r4.

Also not mentioned often is the fact that many cameras have back focus/front focus problems, whereas the combination of PDAF and contrast AF that mirrorless cameras have basically eliminates this problem.