In regards to your second point, I will point you to the oft-linked https://wiki.alopex.li/LetsBeRealAboutDependencies .
Finally, your third point. Although much of the ecosystem is changing at a rapid pace, core and major packages, the ones most directly depended on, have either made very strong commitments towards stability, have a proven track record of having few or no breaking changes or both. Additionally, due to the nature of the package manager (and static linking), it's very easy to freeze the churning sections of the ecosystem for your application, use the important dependencies and even patch bugs you're encountering.
Additionally, the fact that rust's ecosystem is advancing at a rapid pace means that, well, it's advancing at a rapid pace. Most packages are high-quality and useful, and many are hugely advanced from what other languages have to offer, like the serde and regex crates. This reflects on the applications built with these libraries - you're probably heard of ripgrep, originally built almost purely to test the regex crate, or JQL, built on serde_json. There are many more amazing crates than I could possibly mention, and many more software projects like OneSignal's notification systems that showcase the amazing way the projects in the Rust ecosystem have been put together.
In short, most of the downsides that you mentioned are really mostly positives, and these positives do affect the applications a lot. Rust does have negatives, but it has plenty of positives, all of which have very concrete effects.
This is a bit of a wall of text, but your first paragraph irked me. Also, Gimp, OpenOffice and VLC are already huge. I don't use FileZilla, but I would expect similar.