Yes, it's really hard for people that already regularly drink sugar water to quit the sugar water, but it's not very hard for those that don't drink it regularly to abstain indefinitely. The reason is the gut microbome, which drives your cravings. If you regularly drink it, you have more of the types of gut bacteria that consume it, and they tell your brain to give them more. If you don't regularly drink it, you don't have enough of those types of bacteria to make a dent in your cravings. In other words, you really are what you eat (or more precisely you are what eats what you eat).

There's a large subsection of people that choose various vices. Gambling, drugs, alcohol (I repeat), soda and junk food. To folks that do not partake in these things, it's bizarre behavior. Literally none of those appeal to me, but there's clearly profit to be made supplying them.

Are you asking why people can't seem to stop? Or why you seem to possess that ability? Both are biologically mechanistic like all behavior. Probably similar to why some people will kill for heroine while many don't. Or maybe the same reason your gut bacteria can process certain foods others would die from (peanuts), it's environment plus biology in a complex set of local minima that cause repeated behaviors. Is it surprising a biological system optimized to gorge sugary food as late as 200 years ago struggles to stop now? You may have well starved if you ate just one helping while food was available, discipline around food would be a fools pursuit (like intentionally drinking less water than your fill at an oasis).

Sugar water and junk food taste good and people like myself crave that sweet flavor.

If I'm not careful, I can easily and comfortably guzzle liters of soda in a day.

It's less a hard thing and more a "I'm on autopilot right now, I'm thirsty, and there's a can of soda in the fridge" thing. A similar thing happens with junk food. If I'm hungry, on autopilot, and it's available. I'll probably grab junk food because it's fast, convenient, and tastes good.

You are abnormal for not being able to finish 1 can of soda in a year. Nothing is wrong with you for being like that, you are simply an outlier. There's a reason why Coke is one of the most wealthy businesses in the world.

Disclaimer: I'm highly biased.

I think sugar is an addictive substance just like coffee, and tobacco/alcohol. Sugar and coffee are easier to shake than tobacco or alcohol. If you manage to stay off of it for a few days, you're back to normal. But it's socially acceptable to have a sweet tooth so most people, like with coffee, just keep "using". Some people don't get addicted to things as easily as others. Perhaps you're just one of them?

Most of my information comes from this doctor, Robert Lustig. Here's the latest podcast he was on if you're interested: https://youtu.be/BhEsYJ6gEHY. At around the hour-mark, he starts talking about the addiction side of sugar. There are talks with him that go way back. Around 17 years IIRC.

He's a bit peculiar I suppose, and seems to be on some sort of a crusade against "big food" and "big sugar", but I really sympathize with the guy.

It is, indeed, for some people. It's a core part of why GLP-1 drugs work wonders for some people. Shutting up the "little fat person constantly telling your brain it needs food" is liberating if you have those urges.

Different people have different susceptibilities to getting addicted. And once addicted different people have different amount of brainspace left in their life to quit addictions, also depending on how hard the rest of society makes it to quit.

So, there is neither something wrong with you, nor with everyone else.

Free clean water isn’t available many places so would you rather spend your money on water or a sugar hit? I’m with you on water though it’s so delicious.

Good for you. Can you please convince anyone to do the same?

Is it really that hard for people to stop doom scrolling or to stop inhaling or drinking dangerous chemicals?

They aren't selling these foods and coincidentally they are addictive. They have chosen the most addictive foods to sell - that's what makes them the most money. It turns out prune juice doesn't sell as well as soda, so that guy got fired.