Representative democracy advantages
Representatives can be held to account. E.g. they can be voted out during general elections. E.g. Zac Goldsmith was voted out in 2019 by his constituency. This notion does not apply to constituencies whereby a certain party possesses a safe seat.
Representatives can combine differing demands into a single coherent decision.
Representatives can ensure that the interests of specific sections in society are taken into account.
Most MP's are well educated and are therefore more rational than certain members of the public. E.g. Parliament consists of many individuals who were educated through private schooling.
In a direct democracy, people wouldn't have time to vote but in a representative democracy that position is delegated to someone who is willing to form choices on the behalf of others.