That's something that I have trouble understanding. Why hasn't Canada devoted resources to some sort of amphib capability? Is it against their religion or something?
Few reasons as far as I can tell:
1) The Army doesn't care.
Which means the CDS never advocates to the Defence Minister and thus cabinet that it's important. The Army has always gotten to the theatre they need to whenever they have needed to without too much fuss. The heavy-lift air capability came because the army wanted it and couldn't properly supply Afghanistan. They were pretty agnostic about naval lift, leaving the RCN as the only advocate. And if the Army really didn't want it then why would the Navy dedicate any effort or money into getting it.
2) The army only deploys with allies not independently.
Any foreign geopolitical interest by Canada is also generally also a US interest. If it's not a US interest it's likely also a UK one, or a NATO one. Which means we stage with or through allies almost exclusively. Aside from domestic operations has never had to take independent military action.
3) Other more pressing priorities.
Drawing on the first point, the RCN list of capability gaps includes Fleet Replenishment and AAD. Those are much higher political and military priorities.
4) No existential geopolitical threat that would require an amphib capability.
There is no driving
need for a large amphib capability from a geopolitical location perspective. The nearest foreign threat is Russia, across the other side of Alaska or the arctic and a very frozen ocean. The first mission Canada would do if the Russians invaded the Canadian Arctic would be a search and rescue. Small unit (platoon level) amphib capability is provided by the AOPS and the JSS.
Canada has limited foreign entanglements, any foreign engagement we take is a choice, not an existential threat. Any existential threats to Canada that are not US based are also existential threats to the United States.
During Gen Hilliers tenure (2005-8) there was research into developing an Amphib capability. It would have required approx 10 years of dedicated effort. Instead Canada decided to focus on the creation and training of CSOR an air deployable SOF regiment, which has seen far more action than any Naval Infantry would have in the intervening time (Marine is french for Navy so any Canadian "Marines" would be called Naval Infantry).
Conclusion: Amphib is a nice to have not a need to have for Canada. IMHO there is a list of about 20 things that we should focus on before spending resources on an amphib capability. AORs, AAD, Frigate replacement, improved MCM, more MPA's, increased # of helicopters, Sub replacement, and when that's all done a helicopter carrier of some sort would be a better investment than amphib being more flexible for task group operations (ASW/AEW/ UXV's). And that's just the Navy equipment. The army needs ATGM, attack/scout helicopters and mechanized artillery amoung other things. Airforce needs more replacement fighters, two more C-17 or equivalent, new air refueling capability, the DEW line needs replacing...