Whose to stop the coinbase devs from just draining all accounts and running of with the money? I have been wondering, what would happen if the coinbase developers agree to drain all the funds of all their accounts and run off into hiding?
Its not like anybody will be able stop them or return the coins and their profits will be immense. So what incentive do they have to keep peoples funds safe?
The same kind of business trust and legal things that let an exchange or a bank running I suppose.

There have been exchanges doing what you said in the past, and they have gotten the same legal pursuit as any other business scamming his clients.

Here is some links: https://www.coindesk.com/six-arrested-over-cloned-crypto-exchange-that-stole-e24-million

https://medium.com/datadriveninvestor/investigating-the-40m-binance-hack-c5fba32900f1

Also, at least in the case of bitcoin and ethereum the two most valuable crypto at the moment, and so the more money they can hope to have with, every transaction is recorded on the blockchain so they gonna have a harder time to transform those crypto back to fiat.

You also have to notice that most of the veteran crypto user will advise new users to not let their coins sit on an exchange and instead to store them in an offline secure place, owning our money and replacing the bank being one of the idea behind cryptocurrency, the problem you are describing being one of the reason why.