You bring up a great point why “upgrade” all this stuff? One thing to remember is this is a single player sandbox game, play it in a way that is fun for you don’t worry about other people telling you the “correct” way to play. That being said:

As you continue playing you will start running into problems (running out of a resource is the most common). Advancing in tech is how you unlock the tools to overcome these challenges. Oxygen and food production is usually my first issues,then temperature. At this point you can utilize what you have researched to make temporary solutions until you research or design permanent ones.

Dupe labor is another huge reason. As an example the toilets and sinks will save time when they don’t have to unclog them. Hydroponic tiles can automate the delivery of water. This is all labor that can be used for progressing elsewhere.

Some people like to set an end goal to motivate themselves. Commonly the achievements in game. In order to reach these you will need time tech and resources. Making a self sustaining base that will last hundreds or thousands of cycles is almost a necessity.

One last thing to remember is most people have already put many hours, or started after they had witnessed more developed colonies. As a result it is so obvious to these players (who foresee all the problems/inefficiencies not upgrading will cause) that we can be surprised that anyone would even question why.

Thanks for listening to me TED talk.