The Coinbase Vault is a pretty great idea, but the problem (in my opinion) is the timelock. There was a point when I urgently needed some coins that were locked in the Vault, and iirc they made me wait 48 hours, which is a major pain in the ass.
Well, that sounds like the whole purpose of timelock. Not a negative. Don’t use
any timelock scheme if you may need the money in a hurry. Use a timelock if and only if it makes sense; just don’t use one from Coinbase, because...
I would also recommend that you steer clear of Coinbase altogether - they are a very shitty company and have banned my account for a rather trivial reason. Just don't use them. Get a private key and lock it in a fireproof safe, there's your vault.
This. If you don’t have private keys, then you’re not using Bitcoin. Coinbase is a bank. Be your own bank.
If you need a point-and-click timelock solution suitable for beginners, there exist easy-to-use services which do this with multisig. They can’t cheat you, because your signature
from your private key in your possession is needed for release of funds. I have seen at least one service desiged such that
either your key plus timelock expiry will release funds eventually (so they can’t freeze your funds),
or your key plus their key will release funds immediately. I won’t name any services, because I haven’t used them and can’t vouch for them. Search. Or perhaps someone helpful who
has used these services will chime in...
If you need a timelock involving
no other parties and you know what you’re doing, then—well, you would not be asking about Coinbase.