Hard to draw the line between "C&V" vs "modern" (assuming those are the only 2 categories).
I have an '84 Univega GT (bought new in '85) . Steel frame, 27" wheels (Schrader), downtube friction shifters. 3x6 Suntour, quill stem, etc. Don't think too many folks will argue it's not C&V.
I also have a 2000 Fuji Newest. Steel frame, 700C (presta), Shimano Tiagra, 3x9, threadless headset, etc. Don't think too many folks will say it's C&V. I don't consider it C&V.
So is it age? Is it components? Technology? Something else? A combination?
Maybe the answer is wherever this forum draws the line. In that case there may be 1,000's of answers (opinions).