if weed makes someone feel fulfilled, then they can farm a lot more feelings of fulfillment by using it than the old fashioned way of actually accomplishing things. I think trying to shame people away from it is silly. People who use it will very quickly realize it isnt bad, and then they dismiss everything they heard about it.
There is a monkey paw warning in that it wears off. It wears off in short and long terms; it is less effective the more you use it over time. So be aware that the spectrum for its effects is along the lines of "kind of cool for a little bit" to "everything you love slowly being ripped from your hands". the latter extreme probably being pretty rare and more applicable to heroin.
Otherwise you could make the same 'danger' argument about video games, porn, social media, reading books, painting, co-dependent relationships, etc. Anything that people use to dump their attention / time into rather than deal with anything uncomfortable in their life. The vessels people use are a matter of preference, and tangential to the underlying problem.
There is always an issue with trying to use 1 tool to fix every problem. obsession. Weed usage requires nuance and an understanding of what it is you are trying to accomplish with it. same as any other drug, same as any other tool.
Honestly, if someone wants to do nothing with their life than smoke weed.. who cares? I certainly dont. They might be one of the last people I offer any sort of charity to, but that's about me not them.