MILAN — Who more than a billionaire boy vying for prominence within his family company could be seen wearing Zegna’s Triple Stitch sneakers which, the company admits, exude “success and leadership”?

I’ve tried just about every so-called “perfect” travel shoe on the market. Loafers with cushy foam soles. Minimalist slip-ons that promise slipper-like comfort. High-end trainers that look like they ...