Does the case for C++ in 2020 still exist? Rust and Go are much simpler to learn, can do everything that C++ can and have sane, simple and clean build systems/package managers, not to mention async/await concurrency in the former and channels in the latter.
If you are supporting Windows or Linux, and are supporting the x86 platform, then for me the only reasons to use C++ over Rust are for compatibility with existing code/libraries, or lack of Rust expertise on the team and no time to learn Rust.
If you are working in an embedded environment Rust is still very capable, but the tooling for Rust does not seem at the level of the embedded tooling for C and C++.
You can still use Rust for embedded, and there are success stories to be found in the links below.
[1] https://www.rust-lang.org/what/embedded [2] https://rust-embedded.github.io/book/ [3] https://github.com/rust-embedded/awesome-embedded-rust [4] https://github.com/rust-embedded/cortex-m-quickstart