Unfortunately "the common good" is still determined by individuals with differing risk profiles. It can't be objectively determined as a universal rule for all. This is my take: the vaccines provide protection against severity of symptoms, but this effect drops off after a fairly short period of time, hence the need to keep getting boosters. Alternatively you could catch COVID and natural immunity will provide greater ongoing protection and against more variants (i'm not sure if it reduces transmission to a great extent), however this will also eventually wear off. Recovery rates are very high for young and healthy people. For me, if you are old and/or have conditions that make you more susceptible to severe symptoms from COVID then you should get the jab. Otherwise if you are young and healthy you should probably avoid it and ideally catch it and recover. In the meantime they should continue to enhance the vaccines to provide better protection against transmission, but it should follow the normal process for vaccine approval to capture long term effects of its use.
A couple of things are factually wrong here.
1. Vaccines provide protection against symptoms and this does drop off, but the efficacy against severe cases and - most importantly - death, is longer lasting. So the current science tells us.
2. "Natural" immunity will give you possibly better immunity against the current virus. Natural exposure plus vaccination gives you even broader immunity and better immunity against potential future strains. So the current science tells us. Of course, by not being vaccinated and being exposed you also have a much higher chance of severe disease/death by a factor of around 10.
3. Delta is affecting younger people more than previous variants. Vaccination plus natural exposure (which will probably happen long-term) is better than natural exposure, both in terms of broad immunity and well, AVOIDING DEATH
Now, you might say "I'm healthy, I'm gonna roll the dice, get exposed naturally, I'll probably live and I don't have the hassle or the (incredibly tiny) chance of a serious adverse reaction to the vaccine". That's your prerogative - the maths doesn't really stack up, and you'll be a higher risk of infecting loved ones, but sure, be one of those people.
The latest anti-vax propaganda (and this is one that really pisses me off) is that natural immunity is somehow better than vaccine induced immunity. Sure, if you didn't die from the disease the first time you probably have pretty good immunity, but tell that to all the people who died because they had no immunity to begin with.
Get vaccinated - your chance of dieing from Covid will go from very very low to infinitesimal. That's a good deal. And you'll also be protecting others in the community and in your family and friends circle, PARTICULARLY THOSE WHO CANNOT BE VACCINATED FOR LEGITIMATE REASONS.