In my opinion, surfaces are easier to use than constraints in some situations, such as making vehicles. These changes concern me because I’m sure many older games still heavily rely on surfaces, and the developers of some of those games may not have the time to redo those games using constraints.
I suggest having a ‘Compatibility’ option where surfaces are simulated using the constraints system, similar to what was done to lighting. If Roblox is not willing to do this, perhaps we could make a plugin to do it.