There are quite a few 20 somethings here (myself included) but there are a LOT of younger players, too.
Like I said earlier, I don't mind smaller sets existing, I just wish they'd break up the smaller sets with a few big ones now and again. the last two sets were 90 something, and now the next one is, too. There's something to be said about the ease of collecting the smaller sets, but for me the challenge of a bigger set is much more exciting, and it means I trade more frequently to get the cards I need.
For example, it took me less than a month to collect Undaunted. Now what? I have the cards I want, I have a deck I like...... so I wait. I have nothing to trade for, no real reason other than battling to socialize at my league. Granted, I can trade for more of certain cards, especially if it's a trade to help out a younger player, but there's not much in it for me other than my own satisaction. Some of the really big sets can take up to a YEAR to collect, keeping me entertained and engaged the whole time.