NO!
I am in my 50s, and this is the best decade yet ( although 30s and 40s were great too)
My lovely children are adults and we have adult friendships as equals.
No grandchildren of my own yet, but great nieces and nephews, so plenty of little ones to cuddle and spoil, and then hand back to parents to do the night waking!
My mortgage is paid,
I eventually found a job I loved, and am settled in it and got good at it,
I have done my hobbies for years/decades and am very good at them.
I am considered "senior" in many areas, work, politics and hobby related, and my opinion is sought and respected.
I have good friends, 2 or 3 very close friends from every decade of my life.
I have travelled, and experienced a lot, and understand many issues and situations that I didn't understand when I was younger.
I care not one whit about what anyone thinks of me, I am free and single, and do what I want when I want and I wear what I want. I have more personal freedom and more disposable income than at any other time in my life.
There are many other reasons too, but that is just a few reasons why 50s is the best decade yet