This really hit hard. You made the point about how our boundaries have turned into excuses for avoiding growth. We see many young people now , they are confused trying to protect their peace by avoiding responsibility or discomfort and also. Yes testing boundaries is also part of becoming. We grow up when we face challenges, we have the courage to move out beyond our comfort zone.
Life isn't meant to feel comfortable every time and that is fine and even about this balance is still the key when we set boundaries that protects us it gives us the room to change and learn.
A life of comfort leads to a life unlived.