You vaccinate yourself to protect yourself. People who are vaccinated for a disease can and do spread said disease. It's this way for literally everything. The claims that you cannot spread COVID if you're vaccinated were simply false. Vaccination can have a mitigating effect of course, but we were never going to be able to eliminate COVID with something like herd immunity.
The only virus completely eliminated by vaccines is small pox, and that was largely because of a number of ideal factors. The top two are probably that that no animals carried smallpox, only humans. And the second is that infection or vaccination provided lifetime immunity of effectively 100%. This dramatically reduced its potential for mutation and meant that getting rid of it in humans would get rid of it - period.
Coronaviruses, by contrast, are transmissible between humans and animals. This means even if you fully eliminated it in humans, it could, and probably would, come back. This is why flus are basically impossible to get rid of. If you believe CDC numbers then US flu deaths in 2020 were essentially 0, yet now it's back like nothing ever happened. Even the Spanish Flu is still with us as a variant of the common flu. But fortunately most viruses trend towards less lethal mutations over time. Probably natural selection in play - killing your host is not a great path to survival and reproduction.
As for long COVID. I'd rather defer that conversation for a few years. Research on exactly what it is and exactly what causes it is ongoing, and so debating it at this point is just going to be speculation.
But it's quite trivial to see that vaccination will heavily decrease the possibility of transmission - it's like continuously coughing up millions upon millions of viruses vs only re-transmitting a few.
And you are right that in the long term Covid will probably become just like the regular flu, as it mutates to more infectious, but less and less dangerous - but I don't see how it's relevant. At the height of the pandemic not the weakened strains were at play, and you surely know that a^n will either very quickly die out, or very quickly explode depending on the given 'a' - masks, vaccination, and staying home absolutely helped decreasing the possible reach of the disease.
I don't see how you can say these things absolutely helped when at this point in time I wouldn't ask you if you've ever caught COVID, but rather how many times have you caught it. It doesn't matter how many shots you've injected, how many masks you've worn, or whatever else - you've almost certainly gotten COVID, and probably multiple times. Even Antarctica managed to end up with multiple outbreaks.
And furthermore, if you look at a graph of the typical cycle of a flu-like epidemic they all look extremely similar, including the COVID graphs. For instance here [1] is one for the Spanish Flu. Scroll down a bit here [2] to see the US death graph for COVID. It's essentially identical. With COVID there was a narrative attached to each of the waves, but in reality it was a lot like financial analysts. They can explain everything when they know the results, down to why the market moved 0.7% yesterday. But their analysis of what will happen to the markets tomorrow is somehow no better than you'd get from a palm reader.
There's a nice visual here [1] that shows excess mortality instead of relying on COVID numbers. This helps control for different standards in measurement/demographics, to some degree. After all was said and done the difference between countries was pretty small. The US had a relatively poor outcome for COVID and ended up with excess deaths of 434 per 100k. Australia had one of the best (amongst advanced economies), and ended up with 163. There were large relative differences, but the absolute differences were small - those values are (per 100k) 99.72% the same.
And behaviors were not really predictive of outcomes. Gibraltar, for instance, was the first 'country' (they put the micro in micronation) to achieve complete vaccination coverage. The media ran tons of stories on them being a window into a post-COVID future because cases there plummeted. Then the next COVID wave hit and cases skyrocketed there, just like everywhere else. After all was said and done they ended up closer to the US than Australia with excess mortality of 300.
The only virus completely eliminated by vaccines is small pox, and that was largely because of a number of ideal factors. The top two are probably that that no animals carried smallpox, only humans. And the second is that infection or vaccination provided lifetime immunity of effectively 100%. This dramatically reduced its potential for mutation and meant that getting rid of it in humans would get rid of it - period.
Coronaviruses, by contrast, are transmissible between humans and animals. This means even if you fully eliminated it in humans, it could, and probably would, come back. This is why flus are basically impossible to get rid of. If you believe CDC numbers then US flu deaths in 2020 were essentially 0, yet now it's back like nothing ever happened. Even the Spanish Flu is still with us as a variant of the common flu. But fortunately most viruses trend towards less lethal mutations over time. Probably natural selection in play - killing your host is not a great path to survival and reproduction.
As for long COVID. I'd rather defer that conversation for a few years. Research on exactly what it is and exactly what causes it is ongoing, and so debating it at this point is just going to be speculation.