I mean, 1-2 day shipping is a huge part of their consumer-first policy, which is why every seller has got to do FBA -- for the longest time until COVID, the algorithm heavily penalized FBM fulfilled by merchant from ranking in the search results.
Once FBA started failing during COVID due to warehouse restrictions + sellers and 3PL third party logistics centers really stepped up did FBM even become a thing (and Amazon smartly gave access to Prime badges for FBM sellers who could deal with stringent shipping times).
IMHO the other big superpower Amazon has is to force sellers to eat returns and provide retroactive refunds when a product gets recalled.
Once FBA started failing during COVID due to warehouse restrictions + sellers and 3PL third party logistics centers really stepped up did FBM even become a thing (and Amazon smartly gave access to Prime badges for FBM sellers who could deal with stringent shipping times).
IMHO the other big superpower Amazon has is to force sellers to eat returns and provide retroactive refunds when a product gets recalled.