A lot of the oldest cards in magic are absurdly overpowered: Many cards from Urza's Saga, and even Alpha are downright broken. All of the power 9 are old cards (lol original ancestral recall, black lotus and time walk). The weakness of the next series of sets were a kneejerk result of how ridiculously broken cards like this were. They realized eventually that the new cards they were making were just not good, and the game wasn't interesting enough as a result: the average bad card wasn't much worse than the best cards at the time. They wanted to get people to really go out of their way to buy a lot of cards to make sure they got good cards, so they introduced power creep back into the game and released Modern as a format (they essentially rebranded the game).
Magic solved their power creep issues with formatting. You have different formats for deck building: the most popular is standard, which includes the current edition set (m14 atm), the current block and the most recent previous block. The fact that the most current sets are better than the sets from a few years ago is irrelevant, since those cards from a few years ago aren't allowed to be used.
Draft is currently my favorite format.
Other formats allow for them, but WOTC cares a lot less about balance in those formats. Legacy and Vintage are downright dumb, for example.
Edited by Whitewing, 22 February 2014 - 01:33 PM.