People are becoming less, not more, happy. Since the internet era began, every meaningful metric reflects this same picture - self reported happiness levels, mental health medication prescription rates, suicide rates at all ages, number of self reported close relationships, birth rates. Anything you can think of as a proxy for whether people are enjoying life is either stagnant or down.
Of course it's not as simple as saying technology is the cause of all of this unhappiness, but what is clear is that, at minimum, technology is not doing enough to counteract it. And if the technology isn't the cause, then what is it? A generation and a half of some of the smartest people in the world working on expanding the boundaries of what is possible and people are less happy than they were when it started. This is a huge indictment of the tech industry. What happened?
From what I understand, important factors to happiness are family, friends, sense of belonging, sense of purpose, and then more immediate factors such as stress and work/life balance.
Technology is arguably a negative influence on some of these factors like meaningful in person relationships. Also, much of this has more to do with society as a whole (having kids, having close extended families, being in meaningful long term partnerships) than technology in particular.
Let's look at the obvious, social media, which is some of the most impactful technology used everyday by real people. It's been discussed to exhaustion, but these arguably aren't tools that contribute to factors that promote happiness. They optimize for engagement and ad revenue, not happiness. Dopamine hacking =/ happiness boosting.