I guess I'm not too surprised that someone would still ride 23 or 25 mm tires; after all some people willingly ride on Cambio Corsa derailer bikes, or penny-farthings. So, for historical correctness I guess, sure.

But now that the data is undeniable, fat/supple tires are actually faster not slower, even the pros are racing on 30 or 32, who would ride tires narrower than the pros for any reason other than historical re-enactment of the '80s?

My #1 road racer (a late-'80s Davidson) maxes out at 30 mm, and that's not good enough anymore, so I'm in the process of converting it to 650b. I think it can fit 40+ but I'll settle for 38. My sport-touring/rain bike maxes out at 32 because of fenders, so I'll probably get rid of that and build something more suitable for this old clydesdale.

For gravel, 55 mm. "Full suspension" without the weight or maintenance hassles, low psi without the pinchflats, win-win.

Even my petite ex-racer wife doesn't like 28s anymore since she started riding her garvel bike on pavement. Her Litespeed Ti road racer sits unused, and she had me make new light wheels for the gravel bike to take 40+ mm Rene Herse extra-light tires for pavement. The existing wheels will keep the Furious Fred light knobbies for gravel. The Litespeed will be sold off, basically useless since even 650b conversion wouldn't allow a sensible tire size. We won't get much for it, because nobody wants bikes with such skinny tires anymore!