I didn't think so.
Every car either myself, my partner or my family have purchased since the first one 10 years ago have had start stop fitted.
Number of times this system has failed: 0
The only alternator failure I've ever had on a car was my 2001 5 Series, a car which does not have stop start.
I am surprised you know loads of people who have had the opposite experience.
My only experience of a hybrid system is in my current car and I've only had it 6 months, so I don't have enough personal experience of them yet, but I can't imagine they are particularly unreliable either. Why would they be?