As someone who grew up in Canada and actually paid attention, this common line is mostly BS.
If you have an emergency, you essentially have no wait time for an MRI. If you have a condition that can wait, you go into the line and potentially wait for a long time. When the wait times become too long, it becomes a scandal and then improves. Every scandal then gets reported in the USA as stories about how horrible Canadian healthcare is.
Yes, this is the same as in NZ - the thing is if there are not queues for expensive resources (be they surgeons, MRIs etc) then there must be expensive resources sitting idle.
Queues are a good thing in that regard, they indicate efficiency of use, what we mostly argue about in countries with socialised medicine is "how long the queues should be?".
Ideally they are on average just long enough so that they never become empty when the usual various peaks/troughs of demand occur, plus have the capacity to handle all the life threatening cases on an urgent basis
If you have an emergency, you essentially have no wait time for an MRI. If you have a condition that can wait, you go into the line and potentially wait for a long time. When the wait times become too long, it becomes a scandal and then improves. Every scandal then gets reported in the USA as stories about how horrible Canadian healthcare is.