Serious, and almost inevitably danger / criminal- and life-destroying behavior inducing drugs.
It’s addictive, makes you fat, causes diabetes, screws with hormones, metabolism and sugar levels and costing society a fortune. Center of domestic violence usually, car crashes etc.
What’s not serious about it?
Prohibition worked extremely well. The data is unequivocal: https://www.vox.com/the-highlight/2019/6/5/18518005/prohibit.... Hundreds of thousands of lives were saved.