I may have misunderstood your first point but one of the primary reasons Apple is purchasing so many screens is to purposefully reduce the amount of components on the market to block out competitors from reaching demand.
Apple is struggling to source enough components to satisfy it's own demand. By buying up all it can it is able to secure a supply for itself. If there was enough components for everybody it wouldn't have to do this.
I fail to see how paying suppliers to build new factories equates to blocking competitors.
Now you're attributing another motivation to them, and what are you basing this motive on? The secondary effect of constrained supplies? Aren't you just simply assuming that apple is doing this to keep competition out?
And isn't it obvious that actual competition-- companies that like apple saw the opportunity and spent years working on a tablet- aren't likely to need the same component?
And wouldn't any reduction in availability immediately cause all the non-apple suppliers to boost output?
Trying to corner the market on anything they can make more of is a foolish proposition.