Gives individuals the freedom to go where they want and when they want at a fraction of the cost and without the need to wait for transport ships. How many people in Trek can afford to own ships? how many Starfleet ships or bases can afford to let out shuttle craft for a single person on a long journey? What if someone is on a ship in deep space and needs to return to Earth? the ship isn't going to turn around for one person and certainly wont give away a full shuttle craft for one person unless it's a really good reason. Instead they can be given on of these deep space transport pods. Imagine I'm on Starbase 327 and I need to get to starbase 189 for a meeting, there are no direct transport ships and using a shuttle craft for one person isn't worth it or maybe they're needed for more important things. I could slip into one of these transport pods. They could probably build several pods for the cost of a shuttle.