>Edit: The helpful explanation linked in a comment on the question you linked is defective because it applies to all continuous probability distributions.
It contains the sentence "For any distribution, the sum of probabilities always equals 1" without the caveat that the sum is of a countable number of probabilities. It applies to every continuous distribution using the same argument, but with "the sum across all naturals" replaced with "the sum across the appropriate universe."
"the sum across the appropriate universe" for Reals is an integral. An integral can go from -Infinite to Infinite and still equal 1. This is the reason, for instance, why Zeno's Paradox of movement doesn't really forbid all movement.