Yes. In countries like Canada, the term "fixed rate mortgage" maps to what Americans would call an ARM. 25-year fixed-rate mortgages are simply not available to individual homebuyers. 5 years is generally the highest rate at which you don't have to pay a steep (ie, 1000 bps) premium for, essentially, adding a call option on your loan.
Maybe we should split the difference! The best 25-year fixed-rate mortgage currently appears to be 9.75%, which is about 500 bps higher than the best 5-year fixed-rate mortgage [1]. But in 2021 with 5-year fixed mortgage rates near 2%, the 25-year fixed-rate was still around this level. So it looks like the premium has gone down a bit since the last time I checked. Perhaps that's partly a result of the yield curve inversion we have these days, since the Canada 30-year bond yield is presently just 3.2%. [2]
When you wrote “5 years is generally the highest [term] at which you don’t etc.” it sounded as if you meant that for a term of say 10 years you did etc. [The spread between the 5y and the 10y rates is around 100bps.] There is quite a range of terms higher than 5 and lower than 25.
