Do Preamps only Need Two Inputs in the New World?

and, I bought a CD Player with wheels

that’s got me playing CDs (and SACDs) in my main system more often, happily using a Sony XA5400ES I learned about here

I use AUX for my Reel to Reel Player

and, friends bring their equipment here, I can plug into an unused input of my Chase Remote Line Controller so we can instantly compare a variety of things, as well as play their cartridges in one of my tonearms.

Versatility is far more vital than simplicity for me.

I use one input for my dac, one for my phono preamp, one for my sacd player, and one for home theatre bypass. 

I use the input for my dac 95% of the time. I use it when I stream. 

a good pre does what a good pre does sonically and functionally -- like any piece of gear you choose yours based on your needs, sonically and functionally 

whether any specific user needs one at all is also entirely case specific

My Audio Research Reference 6SE has four balanced and four single ended. Even my ARC Ref 3 phonostage has two inputs. 

I guess it depends on how many sources you have. For me, no, two source inputs are definitely NOT enough. Just make sure to use gold-plated terminations on the input jacks that are not connected to anything.