I sort of agree with both of you. I do think they have the staffing and writing to keep the MCU successful. But to
@Sirwalterraleigh 's point, if you don't successfully keep it fresh, and make it a draw, eventually it will grow stale and lose fan base.
One reason Star Wars is what it is, is they have never IMO, made a proper move after the first original 3.
So Yes, if Marvel can pull of Fantastic Four, Xmen and their space odysey that will supposedly include Silver surfer, Nova, Galactus, and eventually Secret war then they will continue to rake in the $$$$.
But reality states, at some point this will end, it can't keep going. But congrats to them for dragging the first story out 10 years and doing it extremely well.