To me it's still steel vs AL and Carbon. AL bikes like Emonda ALR and CAAD12 have convinced enough that AL can mimic similar features as carbon bikes, similarities in weight and compliance and stiffness. As for Ti, just too few to really care IMO.

Steel clearly still popular among ultra-distance and campers. I don't know why carbon all-around bikes aren't made for travel packing. Once that happens, there will be even less reason to buy a steel bike other than preference. Especially now that carbon prices are dropping. Carbon + Tiagra/105 quite reasonable.

OR

Someone will develop ways to hydroform, bend, and butt steel the way they are manufacturing AL. Then there won't be any argument to be had, and it will just come down to preference of material.