One reason the vaccines target the spike protein is that it's how the virus breaks into human cells.

It it mutates to a different spike shape, it's very unlikely that it will keep that breakin power.

Or at least that is the assumption :)

and given that vaccines target only a segment and pretty much the same segment, such mutation based escape from all of the vaccines at the same time is of very high probability - https://journals.plos.org/plosone/article?id=10.1371/journal... . And the fact that the current vaccines don't prevent delta infection seems to confirm it. Whereis natural immunity targets multitude of the segments (and not only of the spike protein) thus naturally providing much more robust immunity.

We need a vaccine for delta. Unfortunately from MBA perspective it is much more profitable to push the current vaccines down the throat of the populace through forced mandates and hysteric propaganda instead of investing additional billions in the vaccine for the mutated virus.

2 shots don't work, thus the 3rd, "booster", then what? the 4th? It is pretty typical for the medical industrial complex to push to sell more and more product in response to low effect, like that opioid dosage increase.

The same could be said for convalescent immunity too.