You have to be careful about comparing the US and Canadian military retirement and pension systems.
Yes, you can retire from the US military after 20 years and draw a half pension. They also have very much an “up or out“ promotion policy. There is no such thing as a career Cpl or Captain in US Service. You don’t make the grade for the next rank- you get told to retire.
Here is a current Basic pay chart. In our system in addition to basic pay there is also BAH basic housing allowance. If you retire the BAH stops. The BAH rate also depends on where you are assigned. Its higher in DC than most places as it it is tied to cost of living if you are assigned government housing BAH stops. There is also additional allowances such as Food,hazard pay ect.