Just that master doesn't actually makes much sense in most git workflows.
If you understand master like you would understand the master/slave relationship in old tech, then of course, master seems to make sense until you realize that there is no slave in that sense or in name. Additional, master is rarely doing anything but having release or hot fixes being merged into it. Arguably dev is the master of the branches.
In other words, master was always a bad name. It is silly to rename it because "racism" but it is at least equally silly to act like master is a much better name than "main" or "live" or "prod" or ... Fuck, the list is long.