This is like asking: Which comes first, the chicken or the egg? Before I explain why I think this, I will first attempt to explain why I find myself in sympathy with both views.
Why does it make sense to view self-esteem as a by-product of worthwhile achievement? It seems to me that Adam Smith was correct in suggesting that when we examine our own conduct and pass judgement on it we are adopting the perceptual position of a spectator. If we view our conduct as praiseworthy this can be a source of “inward tranquillity and self-satisfaction” even if no-one actually praises us (“The Theory of Moral Sentiments”, 1759, III,i,6 and III,ii,1 (here). It is not particularly satisfying to be esteemed if we do not feel that we deserve to be favourably thought of.
Why does it make sense to view self-esteem as a prerequisite for worthwhile achievement? Some people grossly under-estimate their own ability. They are believe that they are destined to fail at everything they attempt to do. Such people need to attain a more balanced assessment of their own capability – greater self-esteem - before it is possible for them to achieve anything worthwhile.
So, how can these views be reconciled? It seems to me that the first view concerns achievement - or conduct, behaviour or performance - whereas the second view concerns capability or potential. Nathaniel Branden has no difficulty in combining both views in his definition:
“Self-esteem is the disposition to experience oneself as being competent to cope with the basic challenges of life and of being worthy of happiness. It is confidence in the efficacy of our mind, in our ability to think. By extension, it is confidence in our ability to learn, make appropriate choices and decisions, and respond effectively to change” (see here).
Abraham Maslow saw satisfaction of the need for self esteem - feelings of adequacy, competence and confidence - as necessary for self-actualization. Michael Hall, a psychologist and personal development trainer, argues that both internal factors (meaning-making or conceptualisation) and external factors (performance) are required for self-actualization. He suggests that people who focus excessively on the conceptual side of things tend to become dreamers and to live in fluff land. Those who focus excessively on performance tend to lose sight of the big picture and become compulsives and workaholics. According to Hall, self-actualization emerges in an experience from creating a rich synthesis of meaning-making and performance – from both knowing and doing ( “Unleashed, A guide to your ultimate self-actualization”, here)
Just as eggs come from chickens, people need some self-esteem before they can achieve anything worthwhile. And just as chickens come from eggs, people need ongoing achievement to maintain self-esteem.