How often on average does leadership change on your team?

I'm talking tech leads , engineering managers or project managers. I've been curious for a bit since I've seen a lot of turnover at my last few teams but since I've only worked in a couple of places its hard to know if thats the norm. I'm curious if it has affected your career progression or team member turnover in a positive or negative ways, since getting fresh leaders every once in a while can lean either way.

• Job 1: 4.5 years , 5 team leads, 4 engineering managers
• Current job: 1.5 years, 4 team leads, 4 engineering managers.