Some find their own minigame in this. One good friend of mine is apparently in it to produce the most powerful deck at the lowest cost - usually via second-hand purchases.
Others just fish for foil cards, which apparently are measurably heavier than normal ones and with a precision scale it's possible to tell whether a booster has one.
I'm not a collector, so I stopped buying them when power creep rendered a second deck of mine useless already.
There's playable game in playing what essentially amounts to no longer "legal" rule sets, but that requires finding a niche partner in an already niche game.
Others just fish for foil cards, which apparently are measurably heavier than normal ones and with a precision scale it's possible to tell whether a booster has one.
I'm not a collector, so I stopped buying them when power creep rendered a second deck of mine useless already.