What [the client] didn’t hire you to do is make them happy, or be their friend. Your decisions should revolve around achieving [the client's] goal, not pleasing the client. And while you should do everything in a professional and pleasing manner, never conflate helping the client achieve their goal with making them happy.
In my opinion, this is some of the best advice on designer-client relationships ever! Too often, as designers, we are tempted or encouraged to sacrifice good design in the name of pleasing the client. But, while this relinquishment might make them happy in the moment, it certainly won't after they realize that the compromised design is not helping them achieve their goals.