Can't all or most cases of `each` be replaced with `map`?

Question

The difference between Enumerable#each and Enumerable#map is whether it returns the receiver or the mapped result. Getting back to the receiver is

Answer 1

You can see the significant difference between map and each when you're composing these enumaratiors.

For example you need to get new array with indixes in it:

array.each.with_index.map { |index, element| [index, element] }

Or for example you just need to apply some method to all elements in array and print result without changing the original array:

m = 2.method(:+)

[1,2,3].each { |a| puts m.call(a) } #=> prints 3, 4, 5

And there's a plenty another examples where the difference between each and map is important key in the writing code in functional style.