The only reason to upgrade is if you need the feature or features Pro provides.  And bear in mind that the features are already installed -- they're simply unlocked when you enter a Pro license key after purchasing it.  It won't take more drive space, so  unless you need more space for other purposes, you don't need to upgrade the drive. 
My Win11 HOME Laptop SPS15 9510 has 315GB of the 500GB SDD used up. If I upgrade to Win11 Pro, will it run reasonably well on this configuration or should I upgrade to a 1TB SDD? 
Should I upgrade from Win11 Home to Pro