Because it honestly doesn't matter most of the time.
In the majority of use cases, your runtime is dominated by I/O, and for the remaining use-cases, you either have low-level functions written in other languages wrapped in Python (numpy, etc.) or genuinely have a case Python is a terrible fit for (eg. low-level graphics programming or embedded).
Why bother making a new variant language with limitation and no real benefit?
In the majority of use cases, your runtime is dominated by I/O, and for the remaining use-cases, you either have low-level functions written in other languages wrapped in Python (numpy, etc.) or genuinely have a case Python is a terrible fit for (eg. low-level graphics programming or embedded).
Why bother making a new variant language with limitation and no real benefit?