The concepts of agency and purpose are intimately connected. An agent is someone who takes an action in an attempt to achieve some desired effect. Purpose is undoubtedly a driving force of beings endowed with a will. The article illustrates very well these concepts.

What I don't agree is that everyone must aim for excellence, or that there is no middle term between all in and none at all. That is a value judgement, not a fact. Furthermore, an objective measure of excellence and success is a very tricky thing to define. People should be driven by whatever they seem fit according to their worldview, whether it is excelling at something or just enjoying life without striving for great accomplishments. Both seem completely valid to me.

Also, even if human beings seem to follow teleological driving forces, to extend this concept to the entirety of existence seems farfetched, to say the least. Purpose underlies agency, not existence. What is the purpose of electromagnetic interactions between particles? What is the purpose of gravitational fields and nuclear reactions? They seem to me completely devoid of purpose.

Finally, the concept of purpose is sometimes mistakenly taken as the concept of meaning. Purpose is a feature of beings with agency; meaning is an intellectual construct of complex minds to make sense of the world and navigate it. Purpose is undeniable; meaning is arbitrary.