I think about this a lot. I was raised in the 70's and 80's and while life was much simpler in technological terms back then, we were definitely just as happy back then as we are today. The only thing that has changed is how we deal with boredom. When I was a kid we did a lot more social things to pass the time. You just did not have the option of plunking yourself in front of a computer and immersing yourself with such low effort. There was TV, but it wasn't like it is today, it was pretty horrible by comparison.
However I have memories of my parents visiting friends for coffee and cards and dragging us kids along. I have memories of going to the cottage on weekends, and friends cottages as well. I am not trying to glorify an ideal past that never existed either. When there was nothing to do the boredom was stiffling.
But overall, to the question of "we're we happier 30 or 40 years ago, I would say no. That is more a question of character than environment. People are predispositioned to happiness or misery (or somewhere along that spectrum) based on the people they are. Would I go back to those days? No way! But I suspect I would find other ways to maximize my quality of life.
Going forward, will technology make us happier? Doubtful. The increased amount of time will be welcome for some who make the most of every situation. For others who are unhappy, they will continue to be, no matter what.
Just my $0.02.