Gambling isn’t introducing substance into user system it is making use of existing brain chemicals.
Social media companies engineered every piece of addictive mechanisms from gambling to alter brain chemistry or reactions of users.
The problem with comparing social media use to tobacco is that they are completely different. It's like saying weed is just like heroin because they both make you feel good. It's reductive and not productive.
The completely anti-social media stance ignores the good parts of social media. People can connect from across the planet and found others who shares the same views or experiences. People who are marginalized can find community where none may exist in their local area. So we should approach this more carefully and grounded.
There are internet forums, chats, e-mail, blogs, there is no inherent need for "big social media" as we know. I do understand those companies made it much easier for average person to participate but still using internet forum or e-mail isn't exactly rocket science.
Here we are on HN, where no one is changing the layout and not doing much to drive engagement. Some days I don't even open any discussion because there is a lot of stuff that is not interesting for me.
"Big social media" companies had already multiple people speaking up explaining that they specifically made changes to drive engagement to hook people up and keep them scrolling without "creating compelling content". They specifically tuned feed algorithms to promote lowest common denominator trash content that makes people react in anger/frustration/whatever and not "creating/promoting compelling content".