I haven't confused anything, weak year is subjective! That's the point, neither I nor Nintendo gives a damn about what you view as weak. 2020 stacks up well against any of those years. The proof is in the pudding, people are buying games in droves because the line up isn't weak to them. AC, 3D Mario classic collection, and Zelda spinoff doesn't stack well against what year? I'm only naming what I believe the biggest sellers will be and besides 2017, I don't see another year really being significantly better than 2020. 2020 already has the Switch's second highest seller after only 4 months. 3D collection will probably beat any other years second best seller. Here ill do a list.
2017: Mario Kart, BoTW, Odessey, Splaton
2018: Smash, Poke Lets Go, Mario Party, Mario Tennis or DK
2019: Poke Sw&Sh, Luigi, Mario Maker, 2D Zelda
2020: AC, 3D Collection, Hyrule Warriors, Paper Mario
Those are i believe the top sellers for each year and honestly 2020 can probably give any of those others besides 2017 a run for their money. The other years need to make up for the thrashing AC will give Smash and Poke Sw/Sh. Then 3D collection will probably beat Luigi or Mario Maker and Pokemon Lets Go. So yes from Nintys perspective despite Covid they look pretty damn good.
Let's tally the sales totals for all these games in a year. Someone necrobump this on 9/9/2021! In fact, let's add a few more games to each year, just to make it a more accurate comparison.
2017: Mario Kart, BotW, Odyssey, Mario X Rabbids, Splatoon 2, Arms, Xenoblade 2, Pokken
2018: Smash, Let's Go, Mario Party, Mario Tennis, Tropical Freeze, Bayo 2, Treasure Tracker, Octopath, Labo, Hyrule Warriors, Torna
2019: Sword/Sheild, Luigi 3, Mario Maker, Link's Awakening, Astral Chain, Yoshi's Crafted World, Dragonquest S, Fire Emblem
2020: AC, All Stars, Age of Calamity, Paper Mario, Bravely Default II (if it even releases this year), Pikmin 3
And just to make it even more fun, let's hold a poll on the site on 9/9/2021. We can ask the userbase here which was the weakest year for Nintendo Switch, from a games lineup perspective. :D