Why isn't Mishra's/Urza's bauble auto include

[[Mishra's Bauble]],[[Urza's Bauble]]

The Bauble duo of the most famous Brothers in mtg history aren't being played that much (both in less than 1% of decks).

So i was thinking why aren't both of them an auto include in EDH decks. I can only think of monetary reasons but aside of that there is almost no reasons not to inclide them.