Two separate aspects of Aspas issue. First is that he is/was not good enough to play for a team aspiring to be in top 4 either in Spain or England. Second, he looked worse than he is, which is exactly what is happening to a bunch of other, much more expensive players at Liverpool, too.
Celta are a great TEAM right now. If they were in Europa league, I'd bet they would go really far there, for example. That is the best Aspas can do.