Do they favour them when presented with a choice, or is it that slop for normies is all open world which skews the data?
Wasn't open world Zelda bashed?
Aren't most switch games level based?
Fortnite, cod, FIFA are level based.
Zelda has never not been open world. If you are referring to BotW specifically, its one of the highest rated games of all time. TotK also widely beloved.
Not sure what you mean by "most Switch games", because Zelda, Mario Odyssey, Xenoblade, Luigi's Mansion, Metroid, AC, etc. are open world. Then things like Mario Kart, 2D Mario, Kirby, Fire Emblem, Ring Fit, etc. are level based. And the, honestly, a plurality are "mini-game based" like Mario sports, Smash Bros., Mario Party, Switch Sports, Wario-ware, etc. where they don't really take place in any sort world or level at all and act more like a single screen arcade game.
But as for your question, yes, game buyers do have a choice with multiple level-based experiences being released by big players every year.
Aside from CoD, which doesn't live or die on the campaign, they seem to underperform to me. The big one that immediately cones to mind to me is Immortals of Aveum, which wore level-based gameplay on its sleeve and got a tepid audience response.