Some jobs have federal regulations so it's not possible to separate the two.
For example, BNSF is railroad owned by the federal government that supplies jobs in several states including Colorado. In the 1970s/1980s, many workers were not only drinking and smoking but there were high as shit on you name it and noone said anything. Today, most signalmen/engineers etc working for BNSF get randoms and are fired for anything even alcohol positive (I'm not joking at all).
So, even if/when it goes legal on a federal level, there will still be companies (like BNSF) that don't give a shit about your recreational life and care more about protecting the lives of others (which makes sense, no?)