Well, there’s a small incentive to buy from /e/, it’s not as if it makes no difference where you buy…
Users who buy directly from /e/ get the “stable” release channel on their phones, which got tested before in the form of “dev” releases, which are running on the phones of the users who installed /e/ themselves.
https://community.e.foundation/t/fairphone-3-update/17575/9?u=anotherelk