It’s the ego that is being unhappy and wants to be happy. Minds that are free from ignorance and egoism is peaceful and joyful as it is and don’t need to feel good and meaningful, or to be happy.
Most minds will try to do something that they like and enjoy, and to achieve something that they want to achieve, to feel good and happy and meaningful.
There’s also nothing wrong with people want to do good and be kind to others because it makes them feel good and happy, but, that’s not the teaching or practice of yoga.
Yoga practice is not about trying to do something to make the ego feels good and happy and meaningful (as this is empowering the ego and egoism) but, it’s to remove the root cause of unhappiness – ignorance and egoism. Once the root cause of unhappiness is eliminated, one will be happy as one is.
When the mind is free from egoism of attachment, identification, desire of craving and aversion, and expectation, one will be peaceful and happy as one is. One doesn’t need to do something, or not do something, to feel good and happy or meaningful. One doesn’t need to take intoxication/alcohol/drugs or to achieve certain results, social status and network, health condition, fitness level, body image, physical and mental ability and good relationships, to feel good and happy and meaningful. One doesn’t need other people’s love, acceptance, support, acknowledgment, recognition, friendliness and companionship, or any entertainment, enjoyment, achievement and success to be happy or feel good and meaningful.
The teaching and practice of yoga is to abandon all these egoism, one will be peaceful and happy as one is. One can perform good actions and be kind to others out of compassion, without selfish intention or expectation of “I am doing all these because I want to feel good and meaningful and be happy.”