I'm not a hard defender of functional programming in general, mind you.

It's just that a ridiculous amount of steps in real world problems can be summarised as 'reshape this data', 'give me a subset of this set', or 'aggregate this data by this field'.

Loops are, IMO, very bad at expressing those common concepts briefly and clearly. They take a lot of screen space, usually accesory variables, and it isn't immediately clear from just seing a for block what you're about to do - "I'm about to iterate" isn't useful information to me as a reader, are you transforming data, selecting it, aggregating it?.

The consequence is that you usually end up with tons of lines like

userIds = getIdsfromUsers(users);

where the function is just burying a loop. Compare to:

userIds = users.pluck('id')

and you save the buried utility function somewhere else.