I forget which comedian said it in a bit they did but it's always stuck with me.
Something along the lines of "If alternative medicine worked we would just call it medicine."
https://youtu.be/HhGuXCuDb1U?t=178
(The whole thing is worth rewatching)
Tim Minchin
"Alternative medicine was either not proved to work, or proved not to work. Do you know what we call alternative medicine that's been proved to work?
Medicine." —Tim Minchin
"By definition", I begin "Alternative Medicine", I continue "Has either not been proved to work, Or been proved not to work. You know what they call "alternative medicine" That’s been proved to work? Medicine."
https://en.wikipedia.org/wiki/Wikipedia:Minchin%27s_Law