I would say the pursuit and journey for happiness is the sweet spot. It's why artists and studios jump right back into some of the hardest processes to go through as they try new things on a new project. After finishing their movie or game, that high of achieving all of those things eventually due down and the question of what happens next settles in.

Like climbing a mountain. Sure all the enjoyment is at the top, but once you learn to enjoy the grand scheme of the whole process, there lies happiness. Anything could happen, but it doesn't quite matter because you're still inspired and driven to climb your mountain.

Not under capitalism. I believe happiness is achievable though, maybe not in the sense of "constant euphoria" though. I think a lot of people misunderstand what it is to be happy... To be healthy, glad to see another day, and fulfilled. To me, that's happiness.

Sure. Happiness is something you need to curate, and it's a state of mind. Lowered expectations can help. I don't need a huge house and expensive cars and lots of material possessions. That is just more to maintain and pay for.

If I have my health and my family and friends are reasonably healthy/happy and I have free time to spend as I please, I'm happy. I try to play as much as I work, that's the balance that works for me.

Yes, fulfillment, stability, and a healthy social life

Yes. Many religious people including myself feel happy. That's one method.

Others find a purpose in their life to drive toward or dedicate themselves to. Be it art, friends, family, work, learning etc.

I would suggest looking at what you want from life, and asking yourself what the first step is to achieving that. I find that I'm at my happiest when I'm keeping on track with my goals.