This is from Ledger
"you can restore a 12-word recovery phrase into any Ledger device. However, we do not recommend importing a 12-word secret phrase that was generated by a software wallet such as Metamask, Phantom, Keplr, Electrum, etc. Recovery phrases created by software wallets are digitally generated and are therefore less secure. On the other hand, if your 12-word recovery phrase was originally created by another hardware wallet like a Trezor One, it is safe to import it into your Ledger device and continue using the same accounts."
I could see the argument that generating on a general purpose computer introduces attack vectors, but they are saying the randomness isn't as good. True?