Indeed it is; there are less flights on the route. I would suggest ( especially if in business class ) that if doing a CBR route to do CBR-PER rather than PER-CBR

PER-CBR does not operate on MON
On Tuesday- Saturday QF720 PER-CBR operates at 00:15 and arrives at 06:00 . Aside from the awful schedule, if travelling in business, be aware that it is operated using a 734 so has convertible seats rather than normal domestic business class

On Saturdays and Sundays there is a decent 15:15 departure which arrives at 21:00 operated using a 73H

CBR-PER is better since it has 1 flight each day using a 73H which departs at 19:20 arriving at 22:00

Dave