The existing VCF 4.x cluster is running on 4 Dell ready nodes with the 7.x ESXi version, but none of the VCF features are being used; therefore, a conversion to a non-VCF vSAN cluster is desired.
VMware vSAN 7.x
VCF 4.x
Move your production VMs off vSAN and rebuild the vSAN 8.x cluster from scratch.
Even though upgrading a VCF 4.x cluster to VCF 5.x is supported, it is not supported to convert it to a non-VCF cluster.