This one is especially interesting. It would be great to see many people with the same interest, combining their efforts over time, resulting in better and better tutorial content for certain niches, like procedural animation. I do believe many of us dream of having that all in one procedural animation solution. Movement, equipment and items usage, environment interaction, game-play events, feet and hand IK that works every time etc. - If these people, in every field, had one go to place to discuss the micro steps required amongst themselves and then bring solutions to the community, it could speed up the process of finding great information by a lot.
Not to forget optimisation techniques, the render pipeline, mesh setups and all that.
Proper procedural 3D audio, UI design, you name it, there are hundreds of people who really know what they are doing and thousands of us who have a few things under our belt. Tens of thousands have ideas that might inspire new ways of doing things.
Not to forget that giant gap between sitting alone and achieving very little for months and actually getting something out to the market, free or paid. There is a massive need for business and entrepreneurship education in this field.
What I miss often, is exactly a hub type of scenario, where inspiration and techniques are combined and easily accessible without the time consuming searches all over the internet.
And of course, some kind of a way to easily expand on community created templates/plugins/assets/materials etc. An Unreal Github/Blender Foundation of sorts, where you upload something, someone improves it and commits an update that the OP can verify and publish. Some open source thing.
Also: Please consider community created game jams, like they have on itch, where anyone can create a jam.
And maybe some kind of an indie games store, like itch/Steam, but with a quality barrier to entry.