Reversing The Decline In Stamp Collecting

Back to the OP, I do not think any proclamations from anyone would have a sustained impact to the hobby. Stamps is just one collectible or hobby (like crafting) among many so lot of competition out there. Those attracting to collecting likely have collecting gene and often interested in history. This could apply to coins, guns, knives, movie memorabilia. Cosplay is popular by some and not likely to see that at a stamp show. You can just go to Hobby Lobby or a craft supply place (AC Moore, Michaels) and see the competition. Some try to associate organized philately to the state of the hobby but collectors do not need organized philately to collect.

If stamps ever had a regular infomercial show on one of those shopping channels like coins, then the market has changed.

Are those Facebook figures for the entire world or just the U.S.A.?