It reminds me, again, of what the Greeks wrote about - the arete (excellence) leads to eudamonia (well-being). What they wrote about is not merely their opinion - it is human nature that applies to everyone.
"Wholeness" comes from the same word as "holy" and "hale" (that is, healthy). Excellence - being the best you can be - is when you are whole and hale (think about the fact disease means dis-ease - lack of ease).
Excellence, if it means anything, means to be the best version of yourself.
Or, as Matthew Kelly put it: "I discovered that when we pursue what is good, true and beautiful, and noble, we are holy, yes, but this is also when we most fully alive and most truly ourselves."