There's no such thing as "safe" or "unsafe" in an unregulated space (hence people saying "no") but if you're asking about relative safety then Coinbase is probably the safest of the centralised exchanges. The alternative to a custodian (like an exchange), self-custody, is "safe" in that it removes counterparty risk but it's "unsafe" in that you are now entirely responsible for keeping your coins in your control which means dealing with the risks of loss and theft.
A better question to ask is: what are you trying to protect yourself against, and what risks are you willing to take? Without insurance (whether that's government provided through a regulatory scheme (which does not exist in crypto), or personally through an insurance provider) you're exposed to a bunch of risks that can be minimised but not removed.
I don't own any cryptocurrency but if I did, I'd either use a specialist custody service or an exchange I trusted. If I was going to self-custody, it would involve multiple hardware wallets across multiple safe deposit boxes.
A better question to ask is: what are you trying to protect yourself against, and what risks are you willing to take? Without insurance (whether that's government provided through a regulatory scheme (which does not exist in crypto), or personally through an insurance provider) you're exposed to a bunch of risks that can be minimised but not removed.
I don't own any cryptocurrency but if I did, I'd either use a specialist custody service or an exchange I trusted. If I was going to self-custody, it would involve multiple hardware wallets across multiple safe deposit boxes.