I don’t think Eichel has been healthy enough in the regular season to show what he can do in a full year. He showed what he can do in the playoffs. Also, the difference can mainly be accounted for with the odd big game here and there. Pettersson’s consistency has been shit this year.
Let's use PPG since that metric is favorable to players who miss a lot of games.
Since joining the Canucks, Miller is 14th in PPG, league wide.
Eichel is 30th during that same time period.
(In raw numbers, Miller is 10th in actual scoring during that time period, while Eichel is 92nd).
Eichel's best finish was 10th in league scoring, while Miller's best finish was 9th. Miller is also 9th in scoring again this season.
What Eichel did last season in the playoffs was great. He also did it on a team that was significantly over the Cap. And he was outplayed by Marchessault, who won the Conn Smythe. That doesn't put him above Miller's superior body of work in my eyes.