Why does the author most likely use the word abundant
over the word "adequate"?

The word abundant fits the context better.

Explanation:

Abundant means more than enough so in the context it means you have more than you need of something. While adequate means decent or satisfactory. Abundant may be referring to someone doing more than what you asked of them, adequate would be doing the bare minimum.

Hope I helped ❤

i can you there : )