Having to maintain and support two things that do almost the exact same thing is unnecessary work for ROBLOX, so as I’m sure you’ve already heard they’d like to phase out gamepasses in favor of developer products, as developer products offer more control. That being said, I agree that the unreliability of saving developer products is completely unacceptable. ROBLOX can keep increasing the number of gamepasses that can be sold as a temporary measure, but ultimately they need to permanently fix the issue if they want to phase out gamepasses. That permenant solution should be datastores working automagically, because in their current state they’re garbage.
Edit: Made a feature request here