I think you might have bad sources. Those 70-90 year old Italians are hiking around the mountains, walking everywhere, and hanging out with their friends and family every day. Obviously not everyone (it's the smoking, mostly) but it's crazy how high quality later life is in Italy for many many people.
Discussion
Your standard for good quality life is significantly lower than mine. My standard is surfing, playing football in full size stadium, never seeing a doctor and taking no pill to the very last day I am breathing. Going for a walk in the woods on some days just doesn't cut it for me.
It works out for me so far. I am old and experienced enough to not care how much longer I have left in this world. Now, the rest of my life, is just pure enjoyment of all the things that I already know well. My only hope and wish for the future is that one of the random mornings, no matter how many from now, I will not wake up after suffering a stroke in my sleep. I am not being original in this. Just copying from the real life of one person from an older generation whom I had a pleasure of knowing.