There are many people who were/arw still affected by the vaccine.
Some people have immune system overreactions like Guillain-Barré syndrome. This is due to the way your immune system is stimulated and is almost always caused by a virus, very rarely by a vaccine. Damage from Guillain-Barré syndrome can last long-term, but that's due to what your own immune system did, not to the vaccine which is already long gone. So far it has only been observed after Astrozeneca vaccination, not the mRNA vaccines.
In some cases heart inflammation or blood clots have been caused by the mRNA vaccines, but that only happens quickly after vaccination. If the damage was bad enough, then the effects of that damage can last a long time, but that is extremely rare and it's only due to the existing damage that came at the beginning of vaccination, not from having it in your system way later.
Any issues caused by the vaccine are going to be caused during the short vaccination period. It simply can't stay in your system longer than that.
I never understand those of who don't understand everyones body is different. "oh it's fine for me, so anyone who says it affected them negatively is just an anti-vaxx liar"
It has nothing to do with "your body". RNA is an inherently instable chemical, it doesn't last any meaningful length of time in anyone's body. It's like blowing bubbles in your house and expecting them to still be there the next year. No matter what kind of house you have, those bubbles aren't going to last.