I would say stamp collecting is largely dead. With the exception of old high-end stamps, people don't seem to collect anymore. Stamps that we used to call "mint never hinged" and sell at a premium now are offered for 80% of face value, and still don't sell. You can't even give away used stamps.

I don't know if the government killed collecting by issuing so many stamps, by issuing self-adhesive stamps, or by creating systems where stamps are no longer needed (on-line postage). I just know that most stamps are worthless these days.

Due to precious metals, coins still have a good market. Remember, though, how many coin stores also used to have a stamp counter.