On the discussion here on chainstay length, while I think a good touring bike should have long chainstays, it is my general observation that chain stay lengths on touring bikes stayed long for a while, but more recently is getting shorter over time.

I own or have owned a total of four touring bikes.
2004 LHT (it is now gone, frame had a factory defect), chainstay - 460mm.
2010 Thorn Sherpa (likely older, I bought the frame used in 2010), size 610S, chainstay - 450mm
2013 Thorn Nomad Mk II (the frame had not changed for a few years, not sure when introduced), Size 590M, chainstay - 466mm
2017 Lynskey Backroad, size Large, chainstay - 445mm.

My road bike (2018 Raleigh Grand Prix), size 580, chainstay - 430mm
My rando bike (2015 Velo Orange Pass Hunter), size 590 - chainstay 435mm.

I think the 445mm chainstay on my Lynskey, photo below, would be nice if it was longer but 445mm is adequate. My bike shoes range from size 44 to 45, I have adequate heel clearance. All of my bikes listed above have 175mm crank arms.



The above tire is a 37mm wide Schwalbe Mondial, the fender is 45mm wide. Both are the widest that the frame allows.

I suspect that as more people use bikepacking gear instead of conventional panniers, that bike manufacturers no longer feel that chainstays have to be longer for heel clearance.