OxyContin wasn't changed to reduce high, it was just made harder to crush, to make it harder to IV. It's still just oxycodone. This was purely in response to pressure in the US from misguided or malicious people.
The change to OC to make it hard to crush only applies in the US (which doesn't seem to stop "abuse" of OC, just makes it far dangerous/expensive). Similarly a liver toxin, acetaminophen (Tylenol) is added to many opiates, purely to damage users that take "too much". Doctors often prescribe as little opiate with as much poison as possible, and slowly move patients over to more pure forms once they've proven themselves (by suffering needlessly).
Heroin is just cheaper and easier to get than OxyContin. This seems mostly caused by the massive increase in difficulty for doctors to prescribe medicine and do their jobs. Addiction to opioids is seen as bad, patients get labelled drug-seekers, and doctors that do help patients end up getting severe penalties.
As you point out, in reality, clamping down on pharmaceutical opiates simply leads to people buying products with low quality control or consistency, and that directly contributes to death. (Though note that opiates by themselves aren't that dangerous, and around 2/3rd of overdoses (according to one Australian study) are due to mixing opiates with other drugs.)
The change to OC to make it hard to crush only applies in the US (which doesn't seem to stop "abuse" of OC, just makes it far dangerous/expensive). Similarly a liver toxin, acetaminophen (Tylenol) is added to many opiates, purely to damage users that take "too much". Doctors often prescribe as little opiate with as much poison as possible, and slowly move patients over to more pure forms once they've proven themselves (by suffering needlessly).
Heroin is just cheaper and easier to get than OxyContin. This seems mostly caused by the massive increase in difficulty for doctors to prescribe medicine and do their jobs. Addiction to opioids is seen as bad, patients get labelled drug-seekers, and doctors that do help patients end up getting severe penalties.
As you point out, in reality, clamping down on pharmaceutical opiates simply leads to people buying products with low quality control or consistency, and that directly contributes to death. (Though note that opiates by themselves aren't that dangerous, and around 2/3rd of overdoses (according to one Australian study) are due to mixing opiates with other drugs.)