Metamask is not fully open source.
So can you answer few questions from the above users? it's seed phrase, master private key or each address private key? it's better for you to explain how it's work and why it can access to the whole wallet too.
Both Metamask and Trust Wallet is almost similar where it's contain same risk due to web wallet and closed source. Better to stick with hardware wallet and write the seed phrase in a strong material.