I'll admit to not understanding why, but "consensus" seems to be that the vaccine confers greater resistance to variants than does natural immunity- perhaps the natural immunity is over-fit to the one virus, whereas the spike is a necessary component to the whole family?
That said, I've also seen oft repeated that what you get is immunity*, aka resistance to the worst symptoms. Mild infections are still to be expected as possible, and Covid 19 will join the ranks of common-cold causing organisms.
My impression was rather it's consensus that the vaccine provides more predictable immunity, which is the most important thing if you want to set policy. So recommendation in most countries I checked is to get the vaccine, even if you had Covid, cause it's the same dose for each patient and we have much better data on efficacy, whereas immunity from infection is much less predictable and traceable.
That said, I've also seen oft repeated that what you get is immunity*, aka resistance to the worst symptoms. Mild infections are still to be expected as possible, and Covid 19 will join the ranks of common-cold causing organisms.