Typically, a player defeats their opponent(s) by reducing their life totals to zero, which is commonly done via combat damage by attacking with creatures
Conversely, all of these cards fit well into the Stasis shell itself, further making the opponents threats less relevant, if the threats can even be cast
Similar to Madness, Delirium was a mechanic chosen for the Shadows block to reflect Emrakul's slow and sure corruption of the minds of Innistrad's inhabitants
We just have so many ways to abuse Teysa
Back in 2019, one of WotC's stated goals for Pioneer was to provide a non-rotating format where Standard cards would rotate into by 2019, Modern's card pool had become so large that it no longer served the needed role of format where you can use your Standard cards after rotation. Pioneer was designed as that retiring home of sorts, where Standard cards could see play after being rotated out