2017, likely that Bernier would've won, but I'm not convinced that he was more well-known than Scheer. Happy to be proven wrong here.
The 2020 result would likely have been the same as it is now. A small contingent of Sloan/Lewis supporters strategically voting would have tipped it to O'Toole.
How does the type of voting affect the number of people on the ballot?
Under a ranked ballot system you can vote for a super marginal party confident that your more mainstream preference will ultimately get your vote if your marginal candidate loses.
This encourages votes for smaller parties
Change the voting process and I could vote for Party Q, then F, then D and have something closer to my true preferences be measurable vs today and give the parties a sense of where they stand with the populace. I’m still not convinced it breaks the binary star in US politics.
Right now, if those are my prefs, I have a choice of voting Q, voting D, or staying home. If Q is a third party, there’s an argument that vote might as well have not been counted or cast (because from today’s voting you can’t infer the true level of support for Q because some Qs cast their ballot for D just on the off chance that R would otherwise win; for the same reason, you can’t tell as much about the true R or D support either).
Alternatively cardinal systems scale trivially (you express how much you like an individual candidate -- independently-- not how much you like a candidate -- comparatively -- to another candidate). You can bullet vote a party line if you really want.
So in a field with a lot of contenders it can favour marginal candidates.
You also end up with an absurdly big ballot. Past, say, five ranks the choices are hardly meaningful.
I’m favourably disposed to this type of voting but those are a couple of downsides.