There has been a shift - an understandable one, and one I by and large support (absent some edge cases) - to move away from causal language for observational studies.

Not to worry, there's three dozen commenters on the way to attest long COVID is definitely the source of their many nonspecific ailments that could easily be ascribed to various other illnesses.

Problem with those conditions and long COVID and CFS are generally similar: No really reliable guaranteed test for most of them, just a series of symptomatic diagnoses and years of ruling out conditions. No offense, but while some people might be full of crap, you sound really insensitive.

If you suppose it's all malarkey and conjecture, what is the problem?

When your doctor says that you're wrong, do you accept his advice or tell him he should be more like Dale Carnegie?

Most logical, rational adults would seek a second opinion, at least in places where those are available; they usually are. Interesting that I said 'some people' and you generalised.

FWIW, if my doctor were unfriendly enough, though, I might do that also.

small study yes, meaningless no

Only the Sith deal in absolutes.