ALU if you lack the creativity to guess at how we can do matterless volumeless storage go read some good sci-fi novels or TV series. It is a staple of the genre - just like the D&D Bag of Holding is the foundation for the exact same thing that happens in most every RPG enabling your bag to put more stuffs than you can possibly carry without ever needing to question how the magic or the physics works allowing you to get on with the story.
If you want the real answer why your bag is 'bigger on the inside' even though it is not a 'ordinary blue police box'....it is because the devs tested the game with inventory limits and found it destroyed the central part of the game which is fast building. The fort defense construction mission that requires you to construct a fort in the next five minutes becomes a plot point that needs to be removed, along with it the entire agile defense premise of the game.
This is a sci-fi game that does not need to be bound by current or near future reality. Complaining about that means you just as well not enjoy Star Trek reruns because everyone knows teleporters are not possible, and how could a hole in the wall make 'Tea, Earl, Grey, Hot' as well as starship parts without smelters.
If you want to play a archaic crafting game there are plenty of games out there that force you to smelt that I can recommend. 'Ark Survival Evolved' does not have replication it has workbenches and forges. Although I recommend multiplayer tribes because making forts is a painful grind in solo play, especially when dinos or people can destroy hundreds of hours work in minutes.
Or go play Wurm Online where you spend IRL months skilling and farming to be a carpenter so you can spend IRL months trying to become a shipbuilder. That game literally forces you to click for each of thousands of pegs that go in the ship along with the hammer animation you seek - although they lack animation resources so most activities just have placeholder wait bars that are so boring to watch many people risk macro bans. Since all this is a lot of work you can create a character and it's holdings that have real world money value which you can sell when you quit.
I play all these games so I greatly appreciate the design decision that Pathea made to not logistically burden crafting and building by using the scifi replicator and it easy storage. I do not need a research paper on how that works, I just enjoy the game. When games are fast for PVP/PVE destruction, then balancing the game for fast construction is what keeps people playing and not rage quitting because the game or it's players destroyed months of work.