Add in the co-op network of credit unions, where you can go to any branch of any of the member unions (50k+ branches last time I checked, but it's been awhile) and it's hard for me to understand why people bother with these big banks.
Since we can't vet a bank's IT infrastructure, having multiple bank accounts seems like the only way to guard against certain risks.
[1] https://www.northbaybusinessjournal.com/article/industrynews...
You can't just go to any branch, you've got to confirm they do shared branching. And then they may likely have withdrawal limits that are pretty low. I recently tried to pull $2,500 cash to buy a project car, and couldn't get it done in one day. If I had a big bank, I don't think it would be an issue; or if I had an account at a local bank or credit union with a convenient branch.