Everything that ends up being useful was a shiny new thing once. Shiny new things get us excited about the future and motivated to build stuff because they give us hope of solving problems that aren't solved yet.

It's worth pointing out that Rust began as a passion project to try and improve the reliability of systems programming. Given that this is still a huge problem today, you can probably imagine it was an even bigger problem back then and Ada had been around for decades by that point, so clearly it had not solved the problem.