(Just to be clear, although the OP is about a YC startup, for sure the same applies in anybody's launch thread.)
Sounds like they also do nice additions such as using the influx of quick grocery services to order the missing bits from the traditional grocery delivery platforms.
What we learned is that when it comes to dinners, many decision makers in the household struggle with making the decision every week about what to eat for the next few days. The randomized recipe button seems to go into that direction. However making relevant suggestions is what we learned so far to be a key in the experience (e.g. considering the current season, what was for dinner in the past week, what is similar to a favorite dish but with a new twist, etc.)
From our existing users we get the feedback that a personalized menu each week and a much more convenient way to order their groceries saves them time and mental energy. For many worth the price. Feel free to give it a try and let me know how it works.
For recipes, Homechart can import recipes from the web and gives you an "I'm feeling lucky" button that randomizes recipes for a meal plan based on parameters like when it was last made or specific tags. For our users, this seems to work well and let's them curate their recipe collection.