I think where something like this gets hairy is when you get to the replication side of things. One would think that a table is a really obvious feature that Roblox could easily add in with everything else, but when it comes to replication, you can see why something like this would be tough to do.
There was actually a post about a TableValue Instance but as you can see in the comments, replicating the table would require putting the table in JSON format (which gets rid of certain metadata like colors, functions, etc) or creating a custom replication system, which would quickly turn into a huge job for roblox and can already be implemented by devs in Lua.
So it’s probably not impossible, but just a lot harder than it seems, and that’s why Roblox hasn’t prioritized something like this (although it would be really nice to use instead of ModuleScripts that can cause memory leaks if used improperly).