Hey there @locoed
It's just a workflow habit for some people, done for many reasons : more visual comfort, easier way to move elements on the time line mainly. Some people will also start by a specific part like first drop or main hook and build the arrangement from there, so you could even start much more further onto the time line. Another useful use is to keep a 1 bar blank before the track start as well as leaving 1 empty bar at the end, this can help to avoid pops & clicks when rendering the final audio or to get a short silence at beginning & end of the track.