SharedGrid LVM isn't always an option with a VPS. For example not every VPS will be be provisioned with LVM.
I agree the "correct" way would be to use LVM and that's how I would do it in a dedicated enviroment but not have every VPS gives you this luxury even from reputable providers.
Also in theory if you had two mount points you could set which one to use at a package level. If you have an NVME raid and SSD raid in the same dedicated server you could sell two packages (NVME and SSD).