Apparently you don't live in Canada. If you did, you wouldn't have to ask why many people oppose JT. He obtained power in a triumph of image over substance. He tends to mindlessly mimic left-lib ideology without much reference to realities faced by ordinary people on the ground. He's from the elites but mouths his concerns about the struggles faced by the middle class without much detailed understanding or knowledge of those struggles. He's an ardent supporter of globalism without acknowledging its deeply deleterious impacts on developed economies, not the least of which are its impact on the very middle class he purports to favor. He thinks the system just needs a little tweaking, mainly in the form of subsidy programs, to work properly. He's promotes large-scale immigration without acknowledging that statistics strongly suggest the most recent generation of immigrants is underperforming in comparison to previous generations, likely due to that little globalism thing that has served to undermine wages. It's easier for him, however, to challenge concerns about immigration with accusations of racism and/or various phobias, a tactic that's become tiresome. But he soldiers on, repeating bromides about supposed labour shortages, despite stagnant wages, and the need for immigration to address a so-called "demographic deficit," both of which are highly speculative notions.
And all of that is just for starters. Trudeau intensely and proudly lacks curiosity, admitting that he doesn't follow the news. His certainty emerges from a preconceived set of beliefs that he simply refuses to subject to criticism or objective analysis. And, to top it all off, he's a terrible communicator who can read prepared and rehearsed speeches but can't think on his feet or coherently speak extemporaneously. I think a more insightful question you might ask is why on earth many voters continue to support Trudeau?