The biggest thing to me imo is that everything was in one account while fdic insurance is only 250k although if chase goes out of business you probably wont need the money anyway. Also specialized startup banks come with a lot of perks for companies and founders and chase evidently didnt (or just had account rep who sucked at his job)
It's quite a lot more important to diversify funds for procedural risk than bank failures, although SVB certainly illustrates that they do happen.
More likely, the bank will put a ~$1b hold on your account while they investigate suspicious transactions, and your options are to whistle, sing, scream, or twiddle your thumbs until they are done.
So having 4-5 total accounts, ideally unrelated to each other in terms of legal owners (differently-named subsidiaries are usually the way to go, I understand, though I am far from an expert in such matters), will enable you to continue to operate your business while bank A does compliance on your accounts.
If you run into a situation where banks A through F all put holds on your account, you need a good RICO lawyer or equivalent. Different class of problem, and different likelihood of happening, and the kind of thing a great CFO plans around.