@Cr1028sorry I missed your questions. The above is a pretty good answer. You will see elsewhere I have posted about long COViD and other damage to the body that this nasty bugger can cause.
I would add to the above that in some ways I agree to what you say above: well if people don’t get vaccinated, isn’t it their problem/fault if they get sick. Yes on the personal level, but no on the public level. It is a drain on the public health system and our healthcare workers deserve to not have to deal with this anymore.
Second, we want to stamp this thing out as completely and as quickly as possible. If kids catch it and are asymptomatic, ok hopefully no harm to the individual kid (again see the above argument about potential complications later) but that passing of the virus leads to mutations. Mutations can lead to various negative outcomes, such as the ability of the virus to overcome the vaccine (or at least certain types of it) and can also change the spread, lethality, and/or profile of the victims. The UK variant is a concern for the first example and the Brazilian for the second. Remember how we were all saying this virus “only affects old people” a year ago? Well not anymore thanks to Brazil’s leadership completely failing it’s people. Now the young are getting hammered because the virus ran wild there and mutated.
Hope that was helpful.