I think what drove this was a comment involving the long term storage of rubber parts. Being on a saw and being in storage present distinctly different situations.
Once on a saw (or car/motorcycle/vacuum coffee pot/whatever) and in place, deterioration isn't a concern until it gets to an extreme. Rubber hardens and becomes less maliable as it deteriorates due to numerous factors that break down the plasticizers, UV inhibitors, elastomers, and other additives (waxes, filler, color, etc.). If the rubber part is in place (on a saw) and it gets hard there are minimal issues because it simply hardens in the right shape that it is needed to do its job.
Storing rubber for later use is different. For me, buying a NOS rubber part has been a crap shoot. If the part has deteriorated to the point that it cracks or breaks during installation it fails to do its job. Most of the time this seems to be caused by storage at high temperatures. But if one is to go to the trouble of long-term storage, or simply slowing down the deterioration, keeping the oxygen, ozone, and UV away from rubber makes a lot of sense.
Sorry for the long answer.