To me least worthy would be somebody winning without making any effort or somebody winning just because or by accident. Verstappen seems to put in the effort so if he does win (and I don't think he will in 2021 anyway), he will, by definition, be worthy.
Personality wise, he appears rather typical to me: modest when starting out/young, cocky after a few years of experience/success, then matures and becomes more reasonable. Doesn't that apply in all aspects of life.