Ask HN: Mnemonic algorithms (bip39, PGP world list) and their upgrade in an app?

Which mnemonic algorithm is the most popular nowadays? I've seen PGP word list and pip39 in use, not sure what else is being used actively. If you need to choose one of them, which one would you choose and why?

And if you are unsure about the choice, how would you make sure your app is able to upgrade it later?