Does anyone know how accurate the estimated CPP benefits are from the my service Canada website? Particularly if you have fewer than the maximum number of years of contributions?

My example, started contributing at age 19, but didn't hit the maximum contribution rate until age 24, and contributed the maximum until age 58, when I will stop working. Which means I have 35 years contributing the maximum amount, and 4 years contributing less than maximum. And then 0 contributions from age 59 to 65.

When I look at the my service Canada website, it has my benefit at age 65 very close to the maximum, is it assuming I will continue to contribute the maximum until that time, or is it doing the calculation based solely on my previous contributions?

P.S. my intention is to wait until I'm 70 to draw CPP, and burn off RRSP/RRIF until then. First world problem, that I assume many of you high earners have, your RRSP is big enough that the mandatory minimum withdrawals in your RRIF will kill you in taxes when you're 80+.

P.P.S. - I'm thankful for this forum because I have no one in the real world to discuss this with. No one wants to hear that my retirement investments are so large, that I'm worried about the taxes at 80+.