SMB over QUIC makes using SMB over the public Internet practical and secure. It is currently only implemented in Windows Server 2022 Datacenter Azure Edition. Support in Samba would allow it to be used by those who do not use Azure or Azure Stack HCI.
I think it is neccessary that GnuTLS starts to implement QUIC in the first place. Andreas, do you know if there is any work in that direction?