In descriptor wallets commands such as dump and importprivkey will not work.
In a descriptor wallet, you own the private keys and you can get them at any time, but you will get them in descriptor format, inside the descriptor will be the xpriv (BIP32 root master private key). With this key, when using third-party tools, you can generate the wallet's individual keys. Just to remind you, Bitcoin Core uses the standard derivation path for descriptor wallets, so:
segwit-compatible: BIP49
native Segwit: BIP84
Taproot: BIP86
See more posts on the same subject:
Why is there no possibility to export privkeys when creating a descriptor wallet
What is the difference between an HD wallet and a Descriptor Wallet, if any ?
[SOLVED] How can one make a Paper Wallet from a Descriptor Wallet ?
How to import an xpriv to a descriptor wallet in bitcoin core?