If you eliminate the odd integers from consideration, you've eliminated an entire class of integers. yet, the set of remaining integers is of the same size as the original.
When you say things like "eliminate a class of bugs", that is played out in the abstraction: an infinite subset of that infinity of machines is eliminated, leaving an infinity.
How you then sample from that infinity in order to have something which fits on your actual machine is a separate question.
Maybe another example is compiler optimisations: if we say that an optimising compiler is correct if it outputs the most efficient (in number of executed CPU instructions) output program for the every input program, then every optimising compiler is buggy. You can always make it less buggy by making more of the outputs correct, but you can never satisfy the specification on ALL inputs because of undecidability.