The census was originally taken 10 years, now it is done every 5.
Some Canadians seem to be afraid that the boogeyman is hiding behind every corner and that by filling in the long form census is going to give him your deepest secrets. So far as I have seen there is no where that you are asked if you cheated on you wife though you are asked about your sexual orientation.
All the data is in aggregate form, so you will not be identified to Revenue Canada. None of the data is cross checked. Your income my be $67,000 but you fill in $5. The $5. Will be what is recorded for the census data.
People who purposely fill out the form incorrectly are just wasting, their own money. They mess up data that is used for building schools, hospitals, infrastucture. If you think that the government of Justin Trudeau gives a rat's *** whether some doofus is going to act like a toddler who doesn't want to eat their vegetables and knowingly fills out a form, that will be used for their benefit, incorrectly.. Well just stamp your feet and say you are not going to eat them, oh I mean, fill out the form.