I dunno. Java was pretty easy to learn for its first decade. Eventually, the complexity of Java and, especially, its toolchain ballooned. By then there were already a lot of Java developers, though.
Rust is a different beast, much more complex from the outset, and not trivial to learn (as Java was). It will grow if that's where the best jobs are, but I don't think it is going to grow in the way Java did, because the difficulty and dynamics are different. There was a good stretch at the beginning where Java was both very helpful on your resume and really easy to learn.
The real comparison is between Rust and C++, even though folks seem to be pushing Rust for web services and internal tooling. And modern C++ is an absolute monster in terms of complexity, often just dancing around problems that Rust solves pretty elegantly with ownership and lifetimes.
Rust is a different beast, much more complex from the outset, and not trivial to learn (as Java was). It will grow if that's where the best jobs are, but I don't think it is going to grow in the way Java did, because the difficulty and dynamics are different. There was a good stretch at the beginning where Java was both very helpful on your resume and really easy to learn.