Does that mean that all the internet registries no longer allocate
/24 (or longer) prefixes that have nothing to do with the actual
Internet topology (these prefixes aka "portable addresses") ? Perhaps
folks from various Internet registries would be able to answer this

  Immaterial. What matters is if providers continue
  to route them.

CIDR works as long as addresses are assigned in a topologically
significant fashion. And this precondition is crucial.

  Not quite. CIDR works. Routing remains stable
  when providers route prefixes in a topological fashion.