It was previously possible without leaving the main view - by clicking the event and editing the title in place.
With the new Material design I can't seem to do the same. I can only click the pencil icon and open another window.
Can it be that Google removed such a powerful feature? I'm using calendar to plan my week (obviously) and I need to shuffle and move existing events a lot. It will triple the time for me doing so. Really frustrating.
Perhaps there's a setting somewhere? I couldn't find it.