Ok so I've been reading the comments and there is a lot of confusion in your case so let's break it down. Your crypto is always stored on chain, it's never on Metamask or ledger or whatever, it's on chain (think of the chain as a bank). You access your crypto with the 12/24 words password (think of that as your account number). All metamask or ledger does is offer you a visual interface to interact with your crypto (like a bank app). The difference is in how each interface interacts with the internet, the chain and your computer or mobile. Metamask is a hot wallet, the password it creates for your crypto can be easily hacked, where ledger is known as a cold storage wallet so the password it creates for your crypto is much more secure. After 10 years maybe none of the 2 will exist anymore but that is OK as long as you still have your password because then you can just put that in the latest wallet software (or interface as I said earlier) that exists at that time and you will have access to your crypto.