That scenario doesn't hold water. If someone doesn't meet the income criterial for one year, this would knock then out of qualifying as a sponsor for three years (unless they happen to live in Quebec) - not just one year. If someone didn't qualify for the first time based on income in 2020 (presumably the issue would have been their 2019 income), then they wouldn't have qualified in 2021 and 2022 either. Also, if they had entered and been selected in a previous year (e.g. 2018) but then failed to maintain the required level of income in 2019, the application would have been at high risk of refusal.
One of the very basic criteria of qualifying as a sponsor is meeting the income requirements for three years in a row and then maintaining that income while the application is sponsored. Failing to meet the income requirements for one single year makes you ineligible to sponsor for multiple years.
Sorry that's wrong. The income requirements for sponsoring families have been affected drastically due to the effects of the pandemic (see: https://www.cic.gc.ca/english/helpcentre/answer.asp?qnum=1445&top=14). Also, my point still stands for the people who were able to apply in 2019, but weren't able to do so in 2020 - by the same logic of "people waiting the longest", the people applied in 2019 would have waited longer than people applied in 2020.