> Which essentially goes at the cost of having Java-style semantic memory leaks (very generally, _any_ kind of keeping-an-object-as-long-as-at-least-one-reference-exists suffers from it)

Rust references work the opposite way. References don't extend the lifetime of their source, and a reference outliving its referent is a compile-time error.

> we still have to pick our poison (personally, I _strongly_ prefer to avoid refcounting, and it does work like a charm in a few very serious million-LoC/billions-transactions projects, but I do agree that opinions may differ).

I have no idea what the hell you're talking about, but you seem to suffer from pretty significant misunderstandings.