Most DJ singles were wide-grooved 12” at 45rpm; 33 1/3 for EPs with two tracks on a side.

Even the 10” releases were 45s.

There is no correlation between record size and speed, and literally no one pressed 78s for DJs because Technics 1200s don’t have a 78RPM speed

Wasn't that + radio schedules the reason why songs are still for the most parts ≈3min long?

And if we want to talk about longer songs... Alan Fitzpatrick - We Do What We Want ? As a more popular example.