Formulas can get pretty complex in Google Sheets (or any spreadsheet for that matter), and the one line formula bar raises the annoyance bar. Being able to extend the formula bar is a godsend!
Excel already has the ability, and apparently Google added the ability back in 2016. I just found out about it last week.
Grabbing the bottom of the formula, the cursor turns into an up down arrow, and you can drag down to make the formula bar larger.
You won’t be able to hit return to put line breaks in your formula, but hitting control-enter will.
This is really exciting!!