This is my observation also. Once drug testing and strict no-alcohol rules went into effect a generation ago, injuries radically decreased.
Example: back in the '80s and early '90s we had people fall into cargo holds. Once intoxicants were strictly banned, hold-falls disappeared. So, employers love drug testing. Bonus: captains don’t have to deal with the dysfunction of sailors sneaking off to bars.
Sailors should love the policy, too. Because when you artificially decrease the number of workers for a profession, the wages rise for everyone else, as employers try to outbid each other for workers. STCW did the same thing. When the USCG made it harder for people with criminal histories to get a MMC, wages rose for everyone else, because the eligible labor pool shrank.
Downside for maritime employers: the shrinking number of applicants. They are bidding for applicants from the same pool as those working a construction job, trucking, etc. In the old days a maritime employer could always hire some guy with a shady past and an MMC. A guy who wanted to lay-low at sea. Now, not so much. The USGC screens out most of the criminal types.
You have to hire the guys that every other employer wants, but the other employer might be perfectly fine with their employees smoking perfectly legal pot after work. And, that employee can also enjoy the most popular drug in America, Wifi, anytime, any place, ashore.
The net effect is that American sailors’ wages increase, as the number of them dwindles.