EDH is especially prone to it as a format, because it's a format which allows almost every card ever printed (with a pretty... inconsistent banlist). This makes for some pretty wild variations in power levels, and the top end tends to be both very samey and very expensive. It's very popular as a format but it only really works because there's a culture of trying to match power levels between decks (to be fair, there's also the fact that 100 card singleton does tend to mean it's hard to be completely consistent, so there's a lot more 'bleedover' between power levels in terms of chance to win in a given match, as well as the >2 player aspect levelling things out as a player obviously in the lead will tend to be ganged up on)