Mainstream medicine sometimes gets things wrong and sometimes is greedy and corrupt, but generally does try to get things right and has checks and procedures in place toward that end.
Alternative medicine almost always gets things wrong, generally doesn't even attempt to validate whether its treatments work, and is absolutely loaded with quacks and grifters.
There is a TON of this in today's discourse. "I'm dissatisfied and let down by the establishment, so I am going to run over here and embrace this vapid sensational populist garbage..."
I agree that the establishment is pretty broken in lots of ways, but to replace it you have to suggest something better. It has to be an actual improvement. Most of the "alternatives" I see put forward are substantially worse than the establishment they are seeking to replace.
If that is the key idea I remain unconvinced: science may not be as objective as we might hope, but politics is the epitome of subjective.