Let's do a like for like comparison:
Ollie Wines
- 2013 pick 7
- 22 years old
- Best 22 player
- Plays as an inside midfielder
- Played 107 AFL games
- Contracted
Dion Prestia
- 2010 pick 9
- 23 years old (when traded)
- Best 22 player (when traded)
- Played as an inside midfielder (when traded)
- Played 95 AFL games (when traded)
- Uncontracted
Pretty similar with the exception of the contractual situation. Player worth based on ability is subjective and the role each individual plays varies based on the players around them and team structure so all you can really do to show concrete evidence in terms of ability is point to statistics. I can't be bothered actually going through it but I think both averaged a little over 25 disposals a game in 2016 (Prestia) and 2017 (Wines). I'm sure Ollie was better in most areas but I don't think the gap is as large as you're making it out to be.