tl;dr1: There are many capitalist worlds, people with that tiger can go live there. There's no point to coming back to earth with your money because of taxes and regulations.

tl;dr2: There are many M class planets with many coast lines and Earth is not seen as a place to retire because it's too loud. You probably can't see stars at night anywhere on earth.

tl;dr3: for a market economy to work most people should be in that market. In star trek billions of people (including some of the most stylish and sexy) live outside that market economy.

tl;dr4: traveling the stars >>>>> moldy beach villa you can't remodel because it's a landmark. There will be no city beach that's not covered in public housing. Any villa, including Piccard's villa will be a historical landmark.

Answer: It's fun pretend. ex: Me earthling, I love art but Picassos cost trillions. I join starfleet and save a space princes. She gifts me a 20k year old cubist like painting. I display it in my eight room starfleet issued apartment on the 50th floor of a building in New Santa Monica. Art nerds from all over the sector come visit me. I have social status now and can get into clubs.