That way Lyft and Uber wouldn't have to necessarily create their own storefronts like Instacart has and the grocery chains would be less worried about being commoditized since the grocery chains would control the customer relationship.
I would definitely like to use multiple grocery delivery services so as to keep multiple grocery stores in business to avoid having Amazon/Whole Foods be a single point of failure, but the grocery chains' delivery is backlogged.
It seems counter intuitive for Lyft and Uber to not be finding ways to keep their drivers. Otherwise they will end up working for Amazon doing Whole Foods delivery. In fact, IIRC Lyft was actively encouraging them to go work for Amazon/WF [1].
[1] https://www.theverge.com/2020/3/27/21197699/lyft-amazon-coro...