Curiosity doesn’t kill the fox. It empowers it!
MetaMask is designed to enable users full control of their wallet. That means, MetaMask will have no control over the data, or the access to users’ wallet, assets or account secrets (like your seed phrase and private keys).
Therefore, if you need to restore your accounts for any reason - a stolen computer, a failed hard drive, accidentally removing MetaMask, or etc, you’ll need your seed phrase.
(*With literally just a click when generating your seed phrase, you could save your seed phrase).
In general, the nature and current state of blockchain applications that allow users to fully control the account data/secret, requires users to back up the seed phrase (and the private key) regardless.
This practice is deemed essential in the industry and communities alike world wide, where it's widely regarded as among first steps crypto users could take to protect their assets responsibly.
On MetaMask, you’ll see some tips to save your seed phrase when you first generate a MetaMask wallet.
While any one of these methods is safe, you should consider saving your seed phrase via multiple methods, and store it across multiple (safe) locations, in case you lose any copies.
Further, if you are curious about the difference of your seed phrase and private keys, please see: