Efheny stayed because ab-Tzenketh is such a remarkable world in every single way, especially compared to Cardassia. There's practically unlimited resources there.
Rhetorical generalities with little substance.
'practically unlimited resources'? Not for her - not for most Tzenkethi. She - they - are slaves. Most, perhaps, willing slaves - due to their genetic make-up and brain-wash. That's the limit of their lives.
'every single way'? Obviously not. If you're talking about positives, that is.