Even if you do believe that it's for "no practical benefit", the value of _x_ in Rust's case is ~156. (I.e. roughly once every three years, when a new "edition" is stabilized.) And the transition is mostly automated.
Speaking as somebody who has maintained several medium sized Rust code bases over the years, I can comfortably say that it's not a big deal.
What _has_ been a big deal, on the other hand, is getting excited about what I can do with extremely unstable libraries, and then spending a lot of time keeping up with their breaking changes. But I'd be a bit silly to complain about this; in each case, I opted in to an immature ecosystem very early on because I was excited about being part of its early growth. I don't expect to have my cake and eat it, too.
Speaking as somebody who has maintained several medium sized Rust code bases over the years, I can comfortably say that it's not a big deal.
What _has_ been a big deal, on the other hand, is getting excited about what I can do with extremely unstable libraries, and then spending a lot of time keeping up with their breaking changes. But I'd be a bit silly to complain about this; in each case, I opted in to an immature ecosystem very early on because I was excited about being part of its early growth. I don't expect to have my cake and eat it, too.