And let me just emphasize again: T&Cs cannot make illegal behavior into something legal. If they're stealing coins or negligently failing to protect coins or negligently failing to protect their domain, that is all actionable. The only thing the T&Cs could do is force the customer to file suit in a specific court or to use arbitration; they can't change the fact that Blockchain has a duty to its customers.
I can't think of any other field where people think, "Eh, I gave hundreds of thousands of dollars to someone and they claim it's now gone, but I should have been more careful."[/i]
You seem to fail to understand how blockchain.com works and how bitcoin works.
Blockchain.com is a tool, helping you handle your coins.
The coins are not in their custody. It's not like Coinbase or Xapo wallet.
The coins are not in the wallet. They never are. They're "on the blockchain".
So it doesn't matter you have a wallet on blockchain.com if you or somebody else use your private key or seed, recover the wallet in - let's say Electrum and spend the funds from there. Obviously blockchain.com will also display them as gone.
So you didn't give your coin to them. And you may very well spend the coins yourself without telling them.
"5.2.1 General
Any Virtual Currency you purchase using fiat currency in the Wallet will be held in the Trading Account. All Virtual Currency held in your Trading Account will be custodial assets held on trust by Blockchain.com for your benefit on a custodial basis on trust for your benefit."
These are the July 2021 Terms; most of the disputes here would be under earlier T&Cs.
I do understand how Bitcoin works. I also understand how finance companies work; if there is any way for them to trade against your assets, they will do so. Otherwise, there's no value in any "wallet" business model. I know that Paypal and other companies are selling digital assets and not actual Bitcoins; while I don't know Blockchain.com's business model as well, I do know that one shouldn't assume ANY "wallet" company is blind to its users' assets.