Yes I agree, sony is so slow in lenses. and when zeiss comes out with a lens, it sure are expensive.
When I switched though, what I was making sure was the question of "Can I do what I can(portraiture) in Canon 5D Mark III with the Sony mirrorless?" IMO, the answer is yes and so I did the switched.
I'm pretty sure it's different in your case with what you're shooting. "For me" a 35mm is wide enough and they have FE35mm F2.8