That is government for you....
I think that the US government wants what is best for US citizens, with the caveat that it assumes that the continuation of a functional government is of benefit to American citizens. There is certainly disagreement, though, about what is best for people.
In the case of psychedelic drugs, I think the government recognized the potential benefits and the potential hazards, and decided that on balance society would be better of without widespread unregulated access to these compounds. I think they were probably right. They made the same decision about marijuana, and I'm less sure about that one.
The default position of the government seems to be to do nothing until people start dying, then they try to put the genie back in the bottle. See leaded gasoline, and drunk driving, and smoking, and the Cuyahoga river. In the rarer cases that they try to prohibit something before it becomes a national crisis, they usually have pretty good reason (aka science) to do so.
But I don't believe the government actively tries to suppress scientific findings in the same way that the oil industry tried to discredit climate science, or the tobacco industry tried to discredit cancer research, or the auto industry tried to discredit safety features and fuel efficiencies. The government doesn't have an industry specific profit motive to deny scientific facts. If anything, it has a motive to push back against the misinformation of these industries, on behalf of the people they represent.
Sometimes it gets complicated, like when individual representatives from Detroit try to defend the auto industry, or from West Virginia defend tobacco, or from Texas defend carbon extraction. In those cases, politicians try to discredit sound science to protect the pocketbooks of their local constituents, at the expense of all other Americans. That's not government fighting against science, though, that's just capitalist industries buying politicians to fight against science.
Trump is one such politician. He defends the profits of capitalism at the expense of American citizens, presumably because he believes that poor people don't matter as long as rich people succeed. He doesn't care if your lose healthcare, as long as hospitals and insurance companies make money. He doesn't care if your environment is polluted, as long as polluting industries are profitable for the owners. He doesn't care how deep into poverty you fall, as long as billionaires get tax breaks. It's all the same story, told different ways.