I 'm with you, truely.
But what you’re describing is just how science works in a world where we’re trying to make discoveries quickly due to our lifespans only being around 75 years compared to the billions or millions or thousands of years for everything else existing.
As long as we continue making discoveries along the way, this is progress. It sucks that we keep getting things partially wrong sometimes, like with asbestos, but we’ll eventually get it right as long as we keep following the process.
The examples given are not problems with science and time-scales. They are examples of the corrupting influence of money. Companies push their product as being fantastic, and deliberately cripple any science that would challenge their profits. Cigarettes are probably the most famous example of this.