I encountered a practice were developers make synchronous functions asynchronous in order to make less adjustments in the future if and when the functions may change to asynchronous. What I would like to know is what is the price paid for such a practice, I assume the cost is in performance but if there is another cost I would like to know as well

const sum = async (a,b) => a + b // Made async as preparation for unknown future changes 

const someAsncFunc = async (...) => {
  ...
  const res1 = await someRealAsyncFunc(...)
  ...
  const res2 = await sum(a, b)
  ...
}