The telly host made the comments as she launches Sky1's own singing talent show Sing: Ultimate A Cappella (previously Sing It).
Discussing rival telly formats like The X Factor, Cat told the Mirror: “I think every big show like that is cyclical, like Britain’s Got Talent or America’s Got Talent.
"It was Opportunity Knocks about 25 years ago – they are hugely successful and then people get bored, and then they put them away for a bit, then they miss them, then they bring them back.”
Cat will be fronting a brand new singing contest this autumn on Sky 1, which begins on October 6.
With absolutely no backing tracks, no instruments and no second chances Sing: Ultimate A Cappella brings together 30 brilliant and diverse a cappella groups in a competition based on raw vocal talent.
Sky says the new series will be "the UK’s first authentic a cappella singing contest".
Across seven episodes, the groups will be tested in three rounds - a medley round, iconic artist covers and a final showdown between two groups – and unlike other shows there will be no backing tracks or instruments to hide behind.
The winner will put out a single with the aim of getting the Christmas Number 1.
Speaking about the series Cat Deeley said: “I couldn't be more excited about Sing It...I remember singing in choir, when I was a kid and loving every minute!
"We have the very best performers on the show - they have no backing tracks and no instruments, just their own incredible voices and talent! The British a cappella scene is so exciting and I'm thrilled to be able to be a part of it."
Sing: Ultimate A Cappella begins October 6 on Sky 1.