Half the things you are describing here are basically just core game systems that should already exist within the product you paid for.

The reason that a lot of more comprehensive mods exist and work for older Bethesda games is that they’ve been around long enough that people have figured out how to essentially hijack the exe itself, and input custom low level c++ commands, usually via a higher level scripting language.

This category of mods is generally called a script extender.

Script extenders exist because the game is fundamentally so limited and/or broken, and propper modding tools do not exist.

Then, people build the fancier mods on top of the script extender mods.

Bethesda is not capable of creating proper modding tools, because their engine and games are fundamentally too unstable, they’re a spaghetti code mess.

Poke one thing here, and something seemingly completely unrelated breaks somewhere else, because they used a hacky solution 4 years ago once, and then that got forgotten about… multiply that by 100 or 1000.

They would have to actually have a base game and engine that is stable and follows consistent rules, ie, they’d have to refactor everything.

But refactoring everything is expensive and takes time and does not produce more money within a a quarter of its completion.

And also, with Fallout 4 recently, well they actually tried to refactor it, and basically they failed; game just has all new classes and categories of bugs now.

They’re literally not capable of meaningfully improving the situation.