It's understandable that he doesn't want to play for a smaller la liga team when he is in contact with Arsenal. Even if he doesn't succeed there it would at least be another big club on his resume and open up the PL market, back to midtable la liga would probably mean that's it for his career unless he really really turns it up there.
He obviously doesn't care that much if he plays or not or else he wouldn't even be here now. He could've pushed for a move last summer because everyone knew how it will go for him but all we got were reports saying he wants to stay.
Besides that i also doubt Betis and Sevilla would straight up pay us 20M for him or agree to a obligatory buy clause, thats a shitload of money for these clubs.