The world has changed and most techs now use 3/8"dr for everything they don't use 1/4"dr.
In a discussion with the world's oldest tool truck guy, he said the major difference he'd seen was when 3/8"dr impacts became popular and strong, he started having to warranty many times more 3/8"dr chrome sockets.
He said, back in the day, a tech was embarrassed to have broken a socket. It was proof he didn't know what he was doing or was using the wrong tool. There would be long explanations of how it was a terminally rusted fastener. Today, he said the young guys just hand him a can full of chrome sockets obviously used on an impact gun and expect new ones.
If Snap-on made an 18" 3/8"dr breaker bar, it would probably result in yet another large increase in socket warranty. But then, there'd probably be a call for an 18" 1/4"dr breaker bar.
jack vines