The higher part is categorically untrue. The 'same' part is only true in a very narrow sense. Yes, vaccinated individuals have peak viral titers that are the same level as unvaccinated. But vaccinated individual titer levels drop off substantially faster than unvaccinated individuals. So, while an immunologically naive individual might be infectious for 5 or 6 days, a vaccinated individual may only be infectious for 1 or 2.
This is exactly what one would predict based on our understanding of the human immune system. Memory B cells that respond to the antigen would start kicking out antibodies. Some will also undergo further affinity maturation with the Delta antigen. Affinity maturation of these B cells will occur much faster since the target is already very close.
>And the vaccine is waning off in 3-6 months. So I don't see how me getting vaccinated is "for the common good".
As stated above, you would be less infectious having had the vaccine.
One thing to consider is that the outcome of COVID is not 'alive or dead'. There is a spectrum of outcomes that are not captured in official mortality statistics. While it's not clear exactly what that spectrum is (e.g. how many long covid cases really exist), I would note that there are a lot of anecdotes out there about athletes that can't climb a flight of stairs 12 months out after covid.