On the issue of is "natural immunity" better than "vaccinated immunity" here's the great man and Nobel Laureate epidemiologist Dr Pete Doherty. Effectively this means that non-vaccinated exposure to Covid Delta gives higher immune response than vaccines, but vaccines mean if you do get it then your chances of dying is much lower.
Once we open up, with high levels of vaccination, we'll likely be exposed to Covid but won't know as symptoms will be so slight for most of us. That will give even better immunity over time.
Lesson is, still get vaccinated peoples