That's simply not true. One of the most, if not the most, common ways to fail an experiment is through contamination and there are at least a dozen different types of bacteria in the average lab that are brutally efficient at outcompeting whatever is in your sample and probably thousands more that are problematic at best. Once your sample is contaminated it is useless because the number of variables out of your control grow several orders of magnitude in an already poorly bounded experiment.
Even if you have the best biosafety hood with proper airflow to pull things away from your samples, even the simple mistake of taking off your gloves in the hood or wafting your hands over petri dishes is enough for some skin cells carrying bacteria to wipe out an entire experiment.
They are, in millions of lab notebooks around the world that will never see the light of day, and for good reason. There are so many more experiments that end with the unqualified final note "samples contaminated" than successful ones that if biologists spent time tracking down the source or even the type of the contamination, we probably still wouldn't have modern medicine.
Is there any kind of survey of all failed experiments and the causes? What are the numbers? What percentage of experiments fails? How can we be sure the successful trials weren't random if the failures aren't reported in any way?
You seem to be conflating all possible modes of failure under the simplistic designation "failed experiment" and setting up impossible standards for record keeping. The clinical trial equivalent of sample contamination is a patient getting hit by a bus minutes after they receive the first treatment of a trial. Sure if its a psychoactive drug you would investigate if it contributed and you can include this tiny little blip of data in the thousands of other pages you give to the FDA but what's the point? The trial was ruined by an unpredictable act of nature and your resources can be much better spent focusing on the other patients than investigating if the driver was intoxicated or if the hospital needs more stop signs, which are entirely irrelevant to whether or not your drug works.
I am by no means advocating that well thought out and executed experiments that fail to provide evidence for the experimenter's hypothesis should be locked in a dusty file cabinet forever closed to study, but those are few compared to the total number of experiments that ended due to clumsiness, sleep deprivation, or too many undergrads in the lab. Science is all just human error, through and through.
Even if you have the best biosafety hood with proper airflow to pull things away from your samples, even the simple mistake of taking off your gloves in the hood or wafting your hands over petri dishes is enough for some skin cells carrying bacteria to wipe out an entire experiment.