As a young guy I rode the vintage stuff when it was new (late 70's, early 80's). I kept my bikes a really long time, but then got away from riding for a while. When I came back to it 15 or so years ago, things had changed a lot, so confusing I went with what I knew, "vintage".
I upgraded over time, did some wrenching myself, etc., so I learned what the effects and pitfalls were. The old stuff, especially Campy, had more compatibility and odd tool problems. New bikes don't need much more than a couple of Allen wrenches. Gearing is wider now with compact doubles, and the rear derailleurs can handle the range. Brifters, faster shifting, so you don't unconsciously slow down while you shift- especially noticeable on a group ride if you try to hang with DT shifters. New Ultegra brakes are so much better than old Super Record! Sealed bearings= less maintenance
Carbon, especially forks and seatposts, saves easily 1 1/2# and also makes for a smoother ride. Modern frames with shaped tubes (including steel like mine) are stiffer in the right places, like the bottom bracket.