supposedly about a 1/3 of mortgages are variable in Canada. But more importantly, fixed mortgages are almost all 5 year terms (or less). That is, every 5 years you have to renew your rate (even though the mortgage amount is for 25 years). That means every year, about 20% of homeowners are updating to the current fixed rate (assuming an random distribution of purchase date). Perhaps a big chunk renewed early in 2020, but by 2025/2026 all mortgaged homeowners will have a new higher rate.

Canadian mortgages have separate amortization periods (say 20 or 25 years for example) and interest rate terms (generally 1-5 years, after which the rate has to be renegotiated -- and you have the option of transferring the mortgage to another lender at that time).

You can also let your rate float with the market, which is called a variable rate mortgage.