STV is a kind of ranked ballot voting system. In the US the term “ranked choice” usually refers to instant runoff voting which is similar to STV but uses a different mechanism for assigning votes so could produce different results. I’m not familiar enough with either to say which is better.
Whichever one is going to get quickest adopted and replace FPTP is better, I think.
I would rather achieve an 80% solution as opposed to failing to achieve the 100% solution because all the energy was spent in squabbling among different better solutions.
The LPC campaigned on 2015 being the last election under FPP, along with ensuring "every vote counts".
When you say "make every vote count" this necessarily means proportional representation (PR). PR is the only viable long term solution being pushed by electoral reform advocates. Some examples of PR electoral systems:
Trudeau has only ever (secretly) wanted instant runoff voting (IRV) to replace the current first past the post (FPP). So when the tide shifted against him, he broke his election promise and bailed on electoral reform.
In either IRV or FPP, many votes will not count at all (>=50%). So neither IRV nor FPP satisfy the criteria for proportional representation (PR).
Note: lots of people use the term "ranked ballot", but this is inaccurate. Ranked ballot is simply a mechanism, and not an electoral system. For example, both IRV and STV use the ranking mechanism, but only STV is considered PR.
So while Trudeau was pushing for "ranked ballot", along with the "make every vote count" messaging, people are right to infer that STV would be implemented. STV uses ranked ballot but is still considered PR.
In Oregon, Measure 117 on the ballot this year will institute RA ked choice voting statewide. Portland already has it for the 2024 municipal elections, and it'll go into effect countrywide for Multnomah County elections in 2026. Very exciting stuff!