The phrase "frailties of" is correct and usable in written English
It refers to the weaknesses, shortcomings, or faults of a person or thing. For example, "The frailties of the system were exposed when the data was breached."
There was only compassion for the frailties of others".
"Let them see the frailties of the system," he said.
Whatever the frailties of Europe's economies, America is in even worse shape.
She does not shrink from hinting at the human frailties of her heroes.
He knew the frailties of his fellow-Alabamians when it came to race.
Their therapy is to play on the frailties of others and themselves, often with dark humour.
I understand the frailties of life better than I ever have.
How do you deal with technology and the frailties of being a human being?
There's a section on the aches and sudden physical frailties of middle age.
"The present prevailed as the frailties of the First Man were passed on to his heirs.
He has been doubted because of frailties of body and, allegedly, mind.
