What's a word that means "someone who leads by example"?
"_ is a good person because he/she leads by example."
...change to something like:
"_ displays strong qualities of a role model".
" _ is the epitome of leadership/responsibility/etc"
A simple term for someone who leads by example is a role model.
Plain or sophisticated, we need more positive role models (or exemplars).
Note: A role model is a person; an exemplar may be a person or a thing.