So far as I am aware the demarcation principle, in Popper at least, serves merely to distinguish science from non-science. A scientific theory is empirically falsifiable while pseudoscience (e.g. astrology) and metaphysics are not.
A certain confusion arises from the fact that Popper also inclines to regard the non-scientific, as specified by his examples, as not intellectually respectable (as 'irrational, unjustified, unwarranted') by any criterion. Astrology is a prime example; he also excludes psychoanalysis and Marxism.
What is unintentionally misleading about this is that there is no reason why on Popper's own grounds the non-scientific has to lack intellectual respectability across the piece. Indeed, take some of his own work - The Open Society and The Poverty of Historicism. These are in no sense scientific works yet Popper plainly regards them as intellectually respectable. As indeed they are with the exception of the chapters on Aristotle and Hegel in The Open Society.
Note on falsifiability
If the Quine-Duhem Thesis is right, then no hypothesis is definitively falsifiable.
The Quine-Duhem thesis suggests that
it is always possible to accommodate any recalcitrant observational evi-
dence to any theory provided that one tinkers around enough in adjusting
the auxiliary hypotheses and ceteris paribus clauses involved in the test
situation. (Robert Klee, 'In Defense of the Quine-Duhem Thesis: A Reply to Greenwood', Philosophy of Science, Vol. 59, No. 3 (Sep., 1992), pp. 487-491: 488.)
K.R. Popper, The Logic of Scientific Discovery, tr. from the German of Logik der Forschung with additional footnotes and appendices, London: Hutchinson, 1959; New York: Basic Books, 1959).
K.R. Popper, The Open Society and Its Enemies, 2 volumes: Volume I: The Spell of Plato; Volume II: The High Tide of
Prophecy: Hegel, Marx, and the Aftermath (London: George Routledge, 1945; revised edition,
Princeton: Princeton University Press, 1950).
K.R. Popper, The Poverty of Historicism (London: Routledge and Kegan Paul, 1957; Boston, MA: Beacon
Nicholas Maxwell, Karl Popper, Science and Enlightenment, Published by: UCL Press. (2017).
Robert Klee, 'In Defense of the Quine-Duhem Thesis: A Reply to Greenwood', Philosophy of Science, Vol. 59, No. 3 (Sep., 1992), pp. 487-491,