I actually feel like 2021 is more like 2009. I could see holiday sales in 2021 edging out 2020. Essentially:
2020=2008 (peak year, coincidentally we got new Animal Crossing games and the global economy tanked. both were considered quiet years from Nintendo after Q1.)
2021=2009 (first year where sales declined YOY)
2022=2010 (pretty big year as far as releases are concerned)
2023=2011 (last major releases with SS on Wii and likely MP4 and Gen 9 on Switch)
2024=2012 (successor launch during the holidays)