Vim is a regular expression system hooked to a 1970s user interface. If you need to apply regular expressions to text files, vim is useful. I used vi to write code for years, but that was decades ago. There's been some progress since the 1970s.
Incidentally, there is nothing inherently wrong with 1970's user interfaces. My car still has a steering wheel just like cars did in the 1970's. And there is a reason for that. Because it works really well.