He was very popular for a long time. He's been PM under 3 US presidents so far: Obama (only for a few months), Trump (part 1), Biden, and will probably be in for part of Trump's second term.

Like all leaders, people get tired of them. That's especially true when there's a global inflation crisis, and every local leader gets blamed as if it's their fault.

I think he's been... fine. There have been some minor scandals, but just the typical stuff where the government helps out politically connected companies. Other than that it's extremely minor stuff like sticking his tongue out in a playful way in parliament, dressing in Indian traditional costumes on a visit to India, taking a vacation at a place owned by a rich friend. Some of the legislation he passed has been good, like legalizing marijuana, implementing a carbon tax, and a major infrastructure bill. Some has been stupid like the "online news" act that tried to get Facebook and Google to pay the major Canadian for-profit news companies for linking to their stuff... rather than addressing the actual issue of their monopolies.

I don't think the Liberal party is particularly inspiring. OTOH, they're so much better than the conservatives. But, because Trudeau reneged on his promise to get rid of First Past The Post elections, they're going to be his downfall in the next election where the left-wing vote is going to split between the NDP and the Liberals, handing the Conservatives a big majority.