Allow custom controls and a gallery
Due to wide variance among different industries, I think Access is best benefited if users are enabled to author and share custom data-bindable controls. That would enable industries to build controls customized to their particular need, and hopefully share with one other, making it easier to develop with Access even for those who don't have the programming expertise to author it themselves. Look at PowerBI gallery as an example of how this can be a success story for Access.
This is a good idea, but I'd be happy with at least 2-3 user-definable properties that we can use for our own purposes. Right now, I use the .tag property for this, but it's kind of a kludge.