Strategic Troop lift isn't done by Amphibs. It's done by planes and cruise liners. Amphibs are for amphibious operations. And its not RCN doctrine, its Army doctrine. And the Army has absolutely no interest in doing amphibious operations (as Gen Hillier found out despite his interest in the concept). This is a casualty of the way we have structured our commands in Canada.
RCN is directed to support forces ashore as a task. And we can do HADR operations and minor unopposed troop movement with AOPS and JSS. That's the extent of it. And I think that's a pretty good place to be.
Amphib is gloriously expensive, difficult and should only be developed IF we have a strategic requirement for it. Which we decidedly do not. I prefer to focus on getting the core need to have capabilities correct before branching out into nice to have capabilities. Amphib is a big jump.
If we were going to spend that kind of effort and money in the RCN look at an Arsenal ships, domestic submarines, more helicopters, drone carriers, UUV's etc...