Indeed. I’m in the middle of aveilus now, but I make a policy that if anyone else wants to daven, I let them. Bear in mind:
1) A Yahrzeit has Kedimo over an Oveil during his 11 months
2) Whereas one can go to great stride for 1 day, it is almost impossible to go to such strides for an entire 11 months, day in day out.
3) Statistically, there are far more days spent as an Oveil, than as a Yahrzeit, because on average one goes thru 30 Yahrzeits per parent, assuming average age difference between parent & child to be 30 years, where the 11 months is approximately 324 days.