This is true. Longer show orders just also generally meant a longer time for the cast and crew to be around each other. When it takes 5 or 6 months to record 22-26 episodes instead of 2 and a half or 3 months to film 10-15 as you pointed out, it just limits the building of those relationships.

Going back to my Star Trek reference (because I'm an obsessive), the movies were always better when they had to use a smaller budget in more creative ways.

I think now that shows have become more expensive to produce, the money gets pooled up to pay actors instead of using them to extend episode orders.

Much of my POV in this is also coming from watching That 90s Show recently, which I thought had a decent first season. And much of what I've mentioned (at least in the case of this show) can be chalked up, in-universe, to the fact that it was Leah's first summer there. So much like the actors themselves, the character is just getting to know a lot of these other people for the first time.

I'm sure that Season 2, with an "extended" order of 16 episodes, is going to be even better, because the friendships were already starting to form. When we hit their "next summer", I guarantee that the show will take off even more.