Mumps is a danger to men past the age of puberty; if I recall correctly, they risk becoming infertile as a result.
Rubella is a danger to unborn babies, causing terrible birth defects--among them deafness, mental retardation, heart defects, or death.
I do question why kids are vaccinated against milder diseases, like chickenpox, which caused about 10 deaths a year before a vaccine was developed. But, in that case, my questioning has nothing to do with the safety of the vaccine, and more to do with whether the immune system is sufficiently challenged by fighting off a full case of a disease, rather than mini-challenged by a vaccine. But where diseases are deadly or highly injurious, I'm firmly for vaccination.
Most boys had mumps and it was a rare infertile man with mumps.
Rubella was a danger to unborn babies in the first trimester iirc. What will rubella be like if the herd does not have natural immunity.
Measles, was a disease that was mostly lethal to children who were sickly of other significant diseases, now we are eliminating natural immunity.
My kids had chickenpox. All kids should have chickenpox.