Things randomly not being available really underwent a step change that hasn't been reversed in the period since 2020. The best solution to that which I found,

Things randomly not being available really underwent a step change that hasn't been reversed in the period since 2020. The best solution to that which I found, in NYC, was to order as much as possible through Amazon Fresh (really Prime Now was better, but for whatever reason they killed it in favor of the worse version). The benefit of that is that it only takes a moment to check if things are in stock, and if they're not in stock, it just won't let me order them. If they are in stock, I bulk order (best example is, as you said, diet soda). Until I moved out of Manhattan recently, the absolute best shopping experience was Gorillas, which had the "not available in the app if it's not available in real life" experience of Fresh, but also delivery in near real-time. I have started meals, found that I was missing an ingredient, and ordered it through Gorillas with no disruption to the meal prep time.