cracked up to be

used to say that a person or thing is not as good as other people say they are

The idiom "cracked up to be" originated in the early 20th century and is derived from the slang usage of the word "cracked," meaning mentally unstable or unreliable. The phrase is used to express disappointment or a realization that something or someone is not as good or impressive as they were previously believed or described to be.

The new restaurant had received rave reviews, but the food was mediocre and not as delicious as it was cracked up to be.
The expensive designer handbag turned out to be of poor quality and not as durable as it was cracked up to be.
The celebrity's performance at the concert was lackluster; it wasn't as captivating as it was cracked up to be.
The job offer seemed promising, but the reality of the position was far less appealing than it was cracked up to be.
The highly anticipated movie didn't live up to the hype; it wasn't as exciting as it was cracked up to be.