I don't think всё alone in the sense of ещё is bookish, i use it in mundane conversations, and your sentence in Russian is perfectly mundane. But it does in my view have a certain tinge of meaning.
Ещё is a straight still, but всё ещё often and всё almost exclusively are used in combination with alternative conjunction a and have a connotation of can't stop + gerund, that is continuing to do something almost against all odds, against one's will, or obsessively. And in всё alone this connotation is stronger. It's usually said with a shade of regret, helplessness or irony.
Eg.
Она его видеть не хочет, а он всё ходит к ней
За окном уже стояла глубокая ночь, а я всё читал
In both, your Russian sentence and in this example всё is used in a clause contrasting with another clause to mean that something continues to be done or to happen despite circumstance described in another clause.
PS: It occurred to me that this всё could be a variant of всё равно which in contrastive clauses means despite that and also still. So
Прошло 2 года, а я всё слушаю
AND
Прошло 2 года, а я всё равно слушаю
although not fully synonymous are still (apropos) very close in meaning