In Canada, everything seems to be fine despite it being legal for a few year now? People who smoked up, still smoke, people who didn’t still don’t. Really depends on culture and how things are being legalized, obviously. I don’t think any reasonable person says it has no negatives, but it’s just being treated as alcohol.
More people smoke/ingest THC now than did before legalization, but drinking also dropped after legalization. Time will tell which is better, but certainly the short term after-effects from THC are far more pleasant than those from alcohol.