Rust competes on performance and portability far better than Ada did at the time. It's also at parity in features and price, whereas Ada lacked proper OO and co

Rust competes on performance and portability far better than Ada did at the time. It's also at parity in features and price, whereas Ada lacked proper OO and cost money until the Air Force paid for GNAT in the '90s. Modern Ada is a nice language, but pre-1995 Ada lost to C++ for a reason. Soon after that, Java showed up and offered a new, easier way to write safe programs, while also locking in the expectation that "modern languages look like C". Pascal, by contrast, simply didn't offer any compelling advantages.