Falling from a horse at 10mph is dangers, falling from any height is dangerous.

We knew lead was poisonous before it was put into petrol, it was chosen because GM could patent it whereas they couldn’t the already known superior additive, ethanol.

We knew about man made climate change over a hundred years ago, it was buried and suppressed for profit.

Thalidomide wasn't tested and sold freely.

Heroine was a good drug for many uses, lack of regulation and care about addiction was the problem. Even today many medications can have adverse effects or cause addiction if not properly used.

These things have nothing to do with the speed of advancement and all to do with deliberate failures. You can advance rapidly and still test and regulate, but obviously thats less likely in a capitalist system that values money over everything.