One thing that has been discovered over the past 50 years and applied over the last 30 or so is that writing a bootstrapping compiler for a young language tends

One thing that has been discovered over the past 50 years and applied over the last 30 or so is that writing a bootstrapping compiler for a young language tends to strongly bias the language towards being good at writing compilers (potentially to the detriment of other features). Compilers are essentially graph algorithms on loosely typed data. I think a lot of the reason it took so long for Rust and Julia to be invented is that they are both not very good languages for writing a compiler in, so in the era where all the new languages had bootstrapping compilers, no one would write a language with the sets of tradeoffs they have.