The idea that you "decide" to indulge in something unhealthy for you, and it was a free decision and companies had nothing to do with it, is a complete joke. We know humans are biased, we know we evolved to like fats more than salad and sugar more than water, we know advertisers influence us, we know companies spend tens of thousands of people's work and billions on advertising and that vastly outpowers a single person's ability to "choose freely", we know companies wilfully mislead and take advantage of our social nature (look at that respectable admirable sports star associated with our product! Look at the work of Edward Bernays and 'Torches for Freedom' getting women to start smoking cigarettes by associating them with the women's liberation movements) and take advantage of our judgement of colour and contrast and intensity (the same product in a cheap box looks less desirable than it in a bright stylish box - and both product, box and brands might be the same company behind the scenes), and our human decision fatigue and temptation for convenience by putting sweets near checkouts. We know companies specifically target children for their suggestibility with methods like adding toys to cereal boxes, advertising during Saturday morning cartoons or loot boxes in games. We know companies lobby for regulations which help them or hurt their competitors. We know society is organised so the big get bigger - McDonalds can outspend a startup Salad bar by millions to one. We know companies pay scientists to lie about the safety and efficacy of their products, and to hide results that say the opposite.

To then whine that fighting back is 'facist' or to suggest that you're so smart you are magically not influenced by any of this is an embarassment. Companies are permitted to operate in society by the collective will of the people, not by divine right. And the people collectively see that a company is taking the piss, they can change the arrangement to improve it. Saying "company, your behaviour is hurting people's collective health, you need to pay some more taxes to cover it" is one way of doing that. If the company then passes the tax increase to you in the form of higer prices, instead of lower profits, that's up to them.

The very framing of it as "sin tax" as if it's a personal failing and not a deliberate corporate abuse of our biological desires and limits, is a kind of victim blaming that anyone "immune to advertising" oughtn't be falling for.