I guess people like Anya so much because it seems that she shows more true lover emotions towards Eric than Vi. Vi talks about teasing Eric by flirting with other men from the get go, already on the first videocall (iirc). The first date - she shows herself to his friend. And she is open to cuckqueening at the first opportunity. Basically she jumps to swinging too fast. The first phase of a relationship, where lovers are crazy into each other, is missing with Vi. Anya, on the other hand, is jealous, сompetitive, she is also cutely shy and nervous when interacts with him. Basically Eric gets this first love phase with Anya, not Vi. With Vi their emotions are closer to fuckbuddies.
It would be shame if Anya exchanges all these deep feelings to Eric for simply sucking some black cocks, that would break my heart