Do you disagree with those statements? Do you need to see evidence before you’ll believe them?\

I disagree with them.
Higher life expectancy - I wouldn't attribute that to capitalism. Further more life expectancy in the US is declining afaik.
Less war - What do you mean? There's a war in Ukraine, one in Palestine, and there's been perpetual war since ...forever. The US war machine always bombs some country, assassinates a democratically elected leader, etc.
Better quality of life - For the 1% at the expense of all the others maybe.

Capitalism is all about profits, not about better products, better quality of life, etc. In fact it's easily against those things if they get in the way of profit. You can see enshittification everywhere.
For example it would be against their interest for a pharmaceutical company to sell the permanent cure for a disease instead of life-long medical treatment. The latter would be subscription-based therefore create more profit. The cancer comparison is quite fitting imo.