Before bar-end mounted shifters the ends had to meet for safety reasons.
Now some bars are curling up in front to allow the praying mantis aero tuck and others are one piece carbon, custom moulded to the riders forearms. They're getting narrower for sure as riders seek max streamline, and the jury is still out on who suits what taking flexibility and distance into account.
Which have you tried and what worked best for you over shorter and longer distances?