So if Chrome/Ledger went bye-bye, you could still do something about it - they conform to the standard to allow importing your private keys into other wallets.
This is true, but only for few coins - Electrum was primary BTC wallet and then some other developers fork Electrum and make wallets for Litecoin, Dash, BitcoinCash and BitcoinGold recently. For other coins supported by Ledger in case they stop to work, users would need to find a way to extract private keys from seed. I think Ledger is now support 28 or 29 coins, and many new ones are in process to be added on that list.