Transgenderism is still in its infancy. There are no meaningful, long-term studies of outcomes when YOUNG PEOPLE are transitioned before puberty. They could very well be disastrous, statistically speaking. Anyone claiming that the "science is settled" is either a fool or a liar. There remains a distinct possibility that 20 years from now, knowledgeable people will look back on the present day with horror.
There is no visible or measurable support for the fundamental thesis of transgenderism: that humans are anything other than binary. FWIW it has been presumed for all of human history that we are indeed binary, and aside from extremely rare biological anomalies (which are not a part of today's discussion) we have been.
While a "free" society demands that individuals can manifest themselves in any manner they like (although they can make themselves the subject of cruel mockery; human nature cannot be repealed), it is a bridge too far to demand that everyone else in society PATRONIZE and reinforce individual delusions about sex/gender. In other words, Bob can call himself "Alice," and dress accordingly. He can even have himself physically mutilated and take hormones to further the pretense, but he cannot demand that everyone else sanction his delusion. That's not HIS freedom, it's MINE.
In many ways, the Canadian government, in its present form, sucks.