Modula-3, like many Wirth-inspired languages, can be described in a few pages with developers understanding those pages. You can be writing useful code in a day

Modula-3, like many Wirth-inspired languages, can be described in a few pages with developers understanding those pages. You can be writing useful code in a day, using most of its features in a week, and probably master it in months to a year. The GC doesn't make it any less simple as that's one component that lets you ignore the complexity of memory management. The component itself can also be simple. Rust being simpler than other programming languages you cite actually means those languages are enormously complex. That is, given how much more complex Rust was to Wirth-style languages, Smalltalk, Scheme, and so on. It has extra stuff. Hence, the extra complexity. The compiler is also harder to write to make all that work.