I got asked about this from a not so experienced pleb wanting to experiment/ migrate from Segwit to Taproot and use both in parallel during transition.

Creating a new wallet file by choosing a file name and setting up a password for the Sparrow wallet file was a downturner for him at that moment. Furthermore, confusion arised about the fact that the user then would have one hardware signing device but several wallet files.

A generic reason to add this could be: Lower the barrier for users to test/ use bitcoin protocol uprades.

However I am unsure if resources should be put into this feature, personally.

One could argure that if someone wants to upgrad to a new protocol version, getting comfortable with multiple wallet files is desirable. As well as keeping complexity of wallet files low seems favourable.