I think there's higher rates of mental illness than people might think. Just most don't realize, due to normalization of behaviors, lack of introspection and/or self awareness, along with 'successfully' coping and not falling off the bandwagon there (i.e. overworking, drinking, many other forms of escapism)
Empathy, compassion, kindness only come from someone with introspection and self awareness (imo). Something that develops once you've come to face your problems and the emotions/difficulties that come with it. Most people end up perpetually running from them, never having to deal with them face-on.
Just unfortunately, for some of us, we get knocked off the bandwagon and get overwhelmed with the weight of it falling on top of us, in addition to our problems catching us all the meanwhile. It's there, where we have to face our problems head-on, with the weight of life bearing down on us, where we are most vulnerable, that we develop a sense of empathy and realize the importance of human kindness and compassion.