Or even better, have ROBLOX do the tweening utilities, so you can sit back and not worrying about pluggin in the same code for each and every project you do.
But certainly, generic tweening libraries are useful - problem is just that a bunch of people, both here and outside of the dev forums do not know how they’ll go about thinking of this feature (and instead uses loops that holds up everything else and has an unpredictable duration) or finding it among free models (if I don’t know it exists already, I’ll probably not look for it. Am I searching for “tween canvas size” in Free Models? not sure if I’ll get results from that specific search.)
So yeah - making it an official feature would mean more people use it in a more standard way, and it would be useful for so many things 
I… might’ve went a bit off-track, sorry >_>