None of these are as good as the protection of your money in a bank. e.g. Coinbase's insurance covers just their 'hot storage', but that's only 2% of your currency. Plenty of exchanges have lost their supposedly secure cold wallets to hackers.
Coinbase is so large that if their cold storage was compromised, the ripple effects on the entire crypto market would destroy immense value everywhere.
Returning coins to users would only be part of the problem. Everyone’s coins would be worth less from the fallout alone.