I very recently used to live in Columbus, OH (#6 on that list). Its a pleasant place to live, but its not all that cheap (especially in the neighborhoods where young people want to live), its definitely shitty for walking/biking/transit, and we got used to saying that restaurants were "Columbus good" because with some exceptions they never would have survived in Philly.

On one hand, I had a detached single family house with a nice front porch, bigger backyard than you can get in Philly, and a garage (the height of luxury), and could walk to some stuff. On the other hand, I was in one of the densest neighborhoods in the city less than 2mi away from the Ohio statehouse and it was a neighborhood of detached single family houses: what a colossal waste of space. And between buying the house (2015) and moving back to Philly in 2021 I could no longer have afforded to the buy on that block.

And at least as far as outdoor space that I care about is concerned, Philly has much better mountain biking than Columbus, El Paso, and Omaha. Tuscon I am assuming is pretty good. Fairmont, the Wiss, and FDR are damn good parks that are accessible by transit/biking for all sorts of activities, plus the birding is good around here (especially during migration season).

Are small cities good places for young people? Sure. Are those particular cities better than Philly? I heartily disagree and stand by my original statement that the list stinks.