I have banked with a huge commercial bank for the past twenty years and never had any issues. YMMV
But there is something to be said about having an actually usable banking website, modern ATMs, and most importantly some support options during non business hours when something goes wrong.
Also being able to reliably find a branch if you are traveling.
While you can argue that support at a credit union may be better when you can get it, there are real advantages to going with a major bank.
Also as someone else said... the fees, minimum balances, etc were ridiculous.
Also for the record, I only tried one but I really didn't feel like making the jump to another bank if the second one didn't work out well.
An example of all of this wrapped up in a credit union in California - School's First Credit Union.
What's great about modern banks/credit-unions is the ability to issue cards that can use payment processors like Mastercard (school's first uses this), making almost every ATM work for you. I was able to make purchases in London without doing anything special.
The account monitoring is also top-notch. I buy gas, driving up to San Francisco and someone buys some shoes in Los Angeles when I had just stopped in San Jose, I get a phone call. I try to purchase more than $X with the card, it won't go through without me allowing it (you can configure your max daily, ofc). Loan rates are great. It goes on and on.
I just don't understand why anyone uses big banks anymore.
Though I get most of my cash through free cashback when I do grocery shopping or whatever.
I look at it now and think about it, but I have to deal with international things and the last thing I want to deal with is trying to get a hold of my bank from ten timezones over.
I've used the same CU for 20 years, the last 8 of which has been 2000 miles away from it.