I wouldn't say every Rust app does, but I do think it has become more normal for Rust apps to have 200-600 dependencies. However when I look at the list, they usually all make sense, unlike with NPM. There are rarely any one-line crates. Actually I haven't seen any yet (except joke ones of course).

There's no way the average C++ app uses 250 packages though. It's usually more like 5. C++ packaging is a huge pain so people tend to use them only when absolutely necessary, and you get huge libraries like Boost primarily because of the packaging difficulty.

I would say Python varies but 150 sounds high. Something more like 50-100 is typical in my experience.