Is your problem with them that they're synthetic, or that it's nicotine? Pouched tobacco like that been used for decades in some places in the world, or even without pouches, just making your own ball and sticking the tobacco under your lip. I'm not sure these countries have a higher rate of GI/gut problems than other places, which kind of would invalidate your entire argument here.
Snus (tobacco pouches you put under your gums) is super popular in Sweden:
https://en.wikipedia.org/wiki/Snus
It is basically the same thing but not synthetic. Supposedly nicotin pouches are not as harmful because they do not have tobacco leaves.
I am a bit ambivalent about it, on one hand people don't smoke as much because snus which means I don't get as much second hand smoke.
On the other hand it is WAY easier for kids to get started on it as they don't need to hide it after they put it in their mouths. I know a few people who are heavily addicted to it (one even keeps one in when he is sleeping) and they all started in their early teens.
You customarily spit out that saliva that’s been in contact with your dip. Swallowing it is way worse for you. When I framed houses the guys that chewed would leave a little trail of brown spots everywhere.
The problems with chewing tobacco are well-known.
BTW, colon cancer is rising among men in their 40s, and there is no known reason why.
My problem is it is an experiment (synthetic nicotine that is socially acceptable) and kids are addicted to it. It's like candy. No one knows or complains because the users are not generating smoke, vapor or spit. They just swallow the synthetic nicotine.
Yes, people have used tobacco products for a long time. However, they have not sucked on them like candy and swallowed the contents 16 hours a day. They spit, exhaled, etc. Chewing tobacco and snuff are not acceptable and they ruin your teeth/gums. Smoking is not acceptable and it ruins your lungs/breathing ability. This stuff is socially OK, because no one can tell you are using it (no spit or smoke).
Check out all the reports of GI issues on reddit (QuittingZyn). This stuff causes all sorts of GI issues from the top of the stomach to the bottom of the bowel.