For much of the month of the November, Canucks top-lines have been allowing a lot more shot-attempts than they themself have been generating.
Here's a good thread on it.
Edit: Also, to point out, the Vegas game showed just how outmatched Miller is in that match up roll. He was legitimately 'eaten alive' here. He's a really talented offensive piece but as a shutdown center he is miscast.
in the vegas game miller at es was on for more shot attempts for (15) than against (13) so you are contradicting yourself citing shot attempts and then using that game as an example. if you dig deeper into that game miller on a stats basis was one of the better canucks, with a relative corsi of 9%.
more importantly, a small sample size and a focus on a single metric and then focussing on a single game and a single player is not a good basis for evaluating a major need like "we need a centre".
during november suter has been out, pettersson has been playing hurt, and the whole team has arguably been on a down cycle on the proverbial biorhythms. you could also make a better argument we need to upgrade pdg on miller's line than upgrade at centre, but even there i'd do it internally for now.