Why would you think that you'd be any happier under another economic system?

There's people who find happiness right now, today. They find love, they take on responsibilities, they have children, they make a life for themselves. There's more to life than economics. Community, family, friends, the adventure of life and the adventures you don't need a penny to achieve.

Instead of trying to change the world, why not first change yourself? Trek isn't about space communism per se. It's about a humanity who has strived to reach its potential, and individuals who are strong and capable enough that they'd succeed in any system (and in many episodes do).

I should point out that regardless of whatever economic system Trek exists under, starfleet is still a hierarchical meritocracy. Jean-Luc is captain because of his discipline, bravery, cunning, and deep ethics. Barclay is not.

Regardless of the material wealth available, there are things to be happy and sad about there too. Riker got all the alien girls, LaForge got a restraining order from the top researcher in warp field theory. Wesley Crusher got a chance in part because of his competence, but due to his lack of merit ended up kicked out of star fleet altogether. Life is still going to have its ups and downs, and your own personal happiness and success will be your own responsibility regardless of what economic system you're under, or what year it is.

Extreme poverty can make someone miserable, but a person who can post to a star trek fediverse page on the Internet isn't in that extreme of poverty.

Epictetus was a slave who could barely walk, but his stoic philosophy gave him power over himself and commanded respect above his station in his world. He taught us to control what you can, accept what you cannot, and to focus on virtue. His path is just one that an individual who is even a crippled slave can find happiness and inner peace.

You can't change the entire planet. But you can change what's in your own head, and you can change yourself, and you can change how things are around you. If you make those changes, then it might surprise you how much of a utopia you can come to live in.