Question about why credit unions beat big banks on overdraft fees

I was reading a report from the Consumer Financial Protection Bureau last week and found out the average overdraft fee at big banks is around $35, while many credit unions charge nothing or just $5 to $10. What really got me was that these fees brought in over $12 billion for banks in a single year, mostly from people who could least afford it. I moved my checking account to a local credit union in Austin two years ago and honestly forgot overdraft fees even existed until I saw that number. The tradeoff is fewer branches and sometimes clunky apps, but for basic checking it has not mattered to me at all. Has anyone here switched from a big bank to a credit union and missed something specific that made you go back?