There are upsides, your program is smaller, better security because a random kid can't pwn your deps, quality and interoperability. What's not to love?
The std making a breaking change is the language making a breaking change. Most mainstream languages guarantee stability, certainly Rust.
> your program is smaller
How so? It doesn't matter if the code is in std or a crate.
> better security because a random kid can't pwn your deps, quality and interoperability
That's exactly what I said: you don't need bigger std, you just need more official crates.
That's their mistake, right there... When you're upgrading software, you presumably want a better version. You can't have something better without changing it. It's a logical contradiction.
>It doesn't matter if the code is in std or a crate. It very much does because you don't need 95% of the random stuff in the crates. Even for something like rand, you need an xorshift and that's roughly it. 25 lines of code, sorted. You can even write it as a copypaste "dependency" without much fuss in practically any language. That, versus importing a whole rand library with lots of different algorithms, deps on crypto, tests, OS random-based seeding, customisability, etc.
>you just need more official crates
I guess that's one solution but it would probably just be a better idea to split std in two SLAs, one is guaranteed for core stuff i.e. the status quo, one is YMMV.