Too much of a good thing

Too much of a good thing is an idiom that is been in use for hundreds of years. An idiom is a commonly used word, group of words, or phrase that has a figurative meaning that is not easily deduced from its literal definition. Often using descriptive imagery or metaphors, common idioms are words and phrases […]
from Grammarist
https://grammarist.com/idiom/too-much-of-a-good-thing/