Ah, but one must avoid the sense of "interesting" as in the Chinese curse, "May you live in interesting times."Having a collection of long lasting developers is not strictly necessary but it makes film developing more interesting
There is also Ansell Adams' advice to thoroughtly learn one film and one developer before doing anything else. I currently use two developers, a Rodinal clone and HC-110. Over the years I have come to understand their benefits and problems. Both of these have a very long shelf life as a single solution. When using Ilford Pan-F I will add D-23 to tame this films contrast. I only mix what I will need.
Your point of using multiple bottles is a good one and one often overlooked. You cannot have oxidation in the absence of oxygen. By avoiding partially filled bottles much of the problem is solved.
Cheers from sunny Florida.