I've had a friend who's been smoking pot since I met him. That must be almost thirty years. Sometimes, when we meet privately and alone, I wish he could talk to me without smoking weed.
On the other hand, I think it's his only way to be more or less warm and unagitated with people. If you meet him soberly, he is quickly fiery, nasty and often unbearable. So he smokes to be more bearable towards himself and other people. We all run towards the Fifty and older people line our lives more and more. I think anyone who takes drugs (and I think they are all modern people) wants to adapt and be a more bearable contemporary. Not realizing that this bearability effort also has its downsides. But now then. Everyone is responsible for himself and you cannot define a person by his consumption of drugs alone.
I feel myself how much strength it costs me to be outside of my work with people simply only privately together and not after an hour to want to search the distance. But maybe that's the right thing to do if you have nothing else to do but talk.
I have respect for drugs. But I also enjoyed it when I was younger and better tolerated the aftereffects. Mentally they made me more uninhibited and I had experiences that I would never have had when I was sober. Our conventional medicine is stuffed with pain killers, they are just legal and generally accepted means. Everyone has to ruin himself as he thinks this is necessary. The stronger the illness, the more people have to take care of each other. Whole identities create themselves around a disease pattern. If you are "lucky" and fall ill with a serious illness at a young age and survive it, your life may be a little different and less illusory. The best thing to do is to stop looking for guilty people and forgive your own foolishness. To have less control over the thoughts and actions of others. Everybody does after all what they want.
You cannot talk them out of it, you can only serve with an example that another accepts as trusting.