So we can both acknowledge that he got injured after signing. What we don't know is how he adapted to what was expected of him at Liverpool. I've never seen the lad play (and I would doubt any of us have) and I'm not saying Williams is/was better but what Williams did have over Davies was that he'd spent the full season training and playing under Klopp.
Maybe Klopp didn't think Davies was ready from what he'd saw of him in training?
Also, there was no Premier League clubs in for him so that's a bit of a weird take.
Williams obviously wasn't ready either but to take such a strong stance in favour of a player you've never seen play and know barely anything about is a bit bizarre. I think I'd trust the manager and his staff on this one.