Fairly sure the younger cohort is deciding largely based on the past performance of the existing government. Justin's Liberals have been in power since 2015 -- for many 18-28 year olds, the Liberal government is the only party they've known / seen. And in that time, have things improved on the housing front?
Or did the government start off campaigning on it as an issue, but then when the issue spiked due to other Liberal policies (mass influx of immigrants post COVID), did they attempt to claim it wasn't a federal government responsibility? And they then flip flopped on that again, and re-assigned the guy they had in charge of the mass, chaotic influx of immigrants to be in charge of figuring out housing (Miller). A decade of promising advances on that file, and a decade of it getting exponentially worse. And it is exponentially worse, you just have to google charts on housing prices / historical trends to see it, there've been tons of articles in the news over the years screaming about it to the ears of deaf politicians. The party swapping leaders last second isn't going to erase that history, one that was supported by the party at large.
For example, the CMHC has a chart of averages/medians for the vancouver region here: https://www03.cmhc-schl.gc.ca/hmip-pimh/en/TableMapChart/Table?TableId=1.10.1&GeographyId=2410&GeographyTypeId=3&DisplayAs=Table&GeograghyName=Vancouver . From 1990 to 2000, the median went from 280k to 360k -- about 30% over 10 years, roughly 3% per year. Even back then it was considered a good move to buy/invest in housing due to the appreciation in value beating inflation targets. From 2015 to 2022 (the end of the tables data), it went from 1.09m to 2.06m -- about 89% in 8 years, roughly 11% per year. And that includes years where the COVID immigration disruption "briefly" flattened the increase -- it was up to 2m in 2018, dropped to 1.6m in 2020, and then shot back up once the flood gates were re-opened. Wages, to the surprise of absolutely no one, can't keep up with that sort of increase: it's completely unhinged. From a younger person's perspective, that's what the Liberals did.
That cohort is also young enough that things like Childcare will only apply to a small % of the group. Likewise, likely, for dental coverage -- many young people in Uni will get extended coverage from any parental work-coverage, and young people who work will have that potential coverage directly. Dental costs are also less 'present' and ubiquitous than housing costs -- you gotta pay rent monthly, but you don't need an annual root canal. Government Dental is a perk more for retired seniors, disabled/long-term unemployed people and middle-aged people who don't have coverage through work -- even the CBC ran stories focusing on the senior demographic for that one (the person highlighted, iirc, was a ~75 year old who'd worked in America most of her life, who is currently still working to pay for her dentures). Hell, even when I was in uni, at least one of my friends, who had coverage, didn't bother going to the dentist for years cause she just wasn't fussed. Even as a middle aged person, I'm personally not that fussed with anything the liberals / ndp promise the senior cohort -- many millenials are jaded enough at this point, that promises for boomers are viewed as things that will disappear by the time we get old enough to qualify, if we get old enough to qualify given how healthcare/GP access has also deteriorated: I fully expect to die younger than my parents. I can understand why an even younger generation wouldn't be in favour of putting in social supports for boomers -- at this point it isn't the boomers who are having to pay the taxes, its the boomers voting explicitly to give themselves perks at the expense of younger generations.
I think Pierre / the cons are a terrible choice, personally. But I can fully understand why the younger folks would be swayed by the idea of change, even if its just smashing things apart like we're seeing in the States. The last decade has been bleak, and there's no tangible reason to think that the promises of the party in charge during that decade are worth anything going forward.
They have direct access/experience with Liberals making promises for election campaigns, and then doing whatever they want once in power. They have direct experience with a Liberal government causing housing prices to skyrocket at rates previously unseen -- the Liberals have literally presided over a period of Canada's history that utterly destroyed the dreams of many younger folks. They also have access to historical information highlighting how much easier it was for older generations, older generations who have voted consistently to 'pull the ladder up' from the next generation. And, most importantly I think, most people aren't fussed with researching years and years of history before voting.
And the disparity on fronts like housing has grown to a point where lots of younger people are basically saying "We'd rather watch it all burn, so you old people feel the same hopelessness as us". And again, I can't fault them for it.
It's not so much about "pro pierre", as it is "pro change". Carney hopefully will do things 'differently', but doing stuff like axing carbon taxes and removing environmental reviews from projects, isn't exactly a "hopeful future" for younger people who are watching things like Jasper and Lytton burn to the ground due to climate change. Carney is essentially an 'older' generation of Conservative, who was parachuted into the Liberal leadership because they feel like the Cons move right gives them an opportunity to move 'right' to garner more of the disenfranchised conservative voters, while the fear of a hard-right wing movement will keep their left-leaning supporters in line. It's a gamble that'll likely pay off, but it's not one that carries a whole lot of 'hope' given the circumstances. There's a reason more 'active' forms of left wing principles, like what you see AOC and Bernie touring on, have more appeal to the younger demo.