For some people that is true but for me it is a hassle that doesn't work.
I just cleaned out my freezer and pantry of expired stuff (really expired, not just a little bit). And, a lot of it was this type of stuff. Stuff that I bought for a specific recipe and then didn't use again.
Yes, theoretically I could find another recipe to use this spice I don't use for anything else or this perishable item that I only used 1/4 of for the recipe. But, it is more likely I have to find 2 different recipes, one for the spice and one for the perishable item. And, that kind of hassle just gets to be more cooking and searching for recipes that I like.
Someone who likes to do a lot of cooking or who likes the puzzle piece aspect of this would like it. But, that just isn't me....