Knowing ahead of time which functions are async is a feature.
It's a big neon sign that says "hey, this function call is expensive". This is a good thing for programmers to easily see and know at the call site.
If you make multiple calls with async/await in a row, the performance issues are plainly obvious at the call site. With "colorless" functions, this information is hidden in a deeper layer. You have to know what the function does on the inside to even know what its performance impacts are.
Also, a nitpick - you can call async functions from sync ones, you just can't access the return value. Sometimes, you don't need to.
Knowing ahead of time which functions are async is a feature.
It's a big neon sign that says "hey, this function call is expensive". This is a good thing for programmers to easily see and know at the call site.
If you make multiple calls with async/await in a row, the performance issues are plainly obvious at the call site. With "colorless" functions, this information is hidden in a deeper layer. You have to know what the function does on the inside to even know what its performance impacts are.
Also, a nitpick - you can call async functions from sync ones, you just can't access the return value. Sometimes, you don't need to.