TW is non-custodial alright but it's not the best example to compare with Coinbase. While one is custodial and the other is not, both are closed source. That means it's not that trustworthy too since there's no transparency and review or audit is close to a few developers unlike open source non-custodial wallets such as Electrum. Check this topic
https://bitcointalk.org/index.php?topic=5244810.msg54332332#msg54332332In my opinion I think both should not be consider good, coinbase.com is just a custodial wallet which means you do not have complete control over your coins, your coinbase account can be controlled in a way you will not be able to make use of your own cryptocurrencies because it has no private key given. Trust wallet is close source, I will not also go for close source because my bitcoin worth more than money. Both of the can not just be considered a good wallet.