Eh. I'm solidly in the middle of this. The problems with the Creation Engine are not make-believe. Changing to a better engine, like IdTech 6, would likely help a great deal. What no one outside of Bethesda knows is how much work and money that would entail, and what trade-offs would be necessary to accomplish it. Doing such a thing tends to go solidly against the grain of what most business leadership people would be inclined to support. Business stakeholders tend to have a laser-like focus on features, so fundamental design changes and underlying platform innovation tends to suffer in most operations. Would going to IdTech 6 make loading screens go away? Probably. Does that matter for showing a good demo in front of the E3 audience? Not so much.
Tetris does not compare. Might as well compare Monopoly to Fallout while you're at it.