Its easy to see why a square cannot be a triangle because it doesn’t require much thinking to know what a square is and what a triangle is and what their relations to each other are; and this is to say that it is easy to see their essential difference. The problem of infinity is not obvious to you because you fail to understand what is meant by a “definite definable actual quantity” and its essential difference to the word “actual infinity”. It is evident to me because I have bothered to carefully analyse the meaning and nature of the two concepts and I happen to have the ability to comprehend why there cannot be an actual infinite amount of numbers.
Ontological Numbers or objective numerical quantities (1 apple, 2 apples 3 apples, etc…), by there very nature, are countable; they always have a definite definable quantity that can, logically speaking, be achieved by addition; and that is only because its parts are finite. A chain of finite points is a countable construct and thus follows the law of addition, and this is because its essential reality as a chain is an expression of its finite parts which have been added together. You cannot logically complete ontological numbers or transcend them by addition, since you can always add one more number, one more part. It is always and forever a potential infinite, and by that rule it is always a finite chain. There is no “highest number”, and all numbers are always a finite number away from each-other. An actual infinity is not a finite number away from a quantity of “100”. There is no reachable or achievable point at which we can stop and say that this is an infinite chain according to its quantity, since this would suggest that numbers can be completed, which we no they can’t. Thus a well developed intellect, as opposed to a child, can understand that an infinity cannot be defined by a real ontological quantities. Given that a quantity is always finite no-matter how much you add to it, it is therefore the case that an “actual infinity” by definition necessarily transcends all logically possible ontological quantities and thus numbers themselves; and is therefore by nature not a actual number or quantity. Thus, like a square is not a triangle, a quantity is never an “actual infinity”.
There is no possibility of an actually infinite number of universes. There is only one ontological infinite, and that is God. God is not a physical quantity.