To unlock objects, I need to manually select every locked object to Unlock it. This is time consuming and obnoxious. Indesign, Illustrator, Sketchup and others use Unlock All to Unlock every object, saving loads of time.

I think where Illustrator's model could be improved upon is to make "Unlock all" artboard specific so that you're not unlocking every object on every artboard which is generally bad for productivity. In Illustrator I find myself continually needing to group everything on the board before I do "Unlock All" and either hide it or drill down into it so I don't accidentally unlock everything everywhere.

In a UX context, I theorize what I'm proposing is exactly how most of us would want it.