In general, once you reach the size of a starship, its volume is at least ten times that of an aircraft carrier, reaching a hundred times is quite normal. This is the most basic scale of interstellar transportation tools.
However, the Galen Republic is known as a Level 3 interstellar power famous for its 'Giant Battleships' and 'Big Cannons'.
Its giant ships are proper 'Giant Ships', and the scale of a 'Giant Ship' is at least planet-level.
So in a certain sense, the Ring Star Ship isn't even the largest model; above it, there are planet-level and even stellar-level ships.
However, the reason why the 'Arc Great Wall' is so famous is that its anti-search capability is far stronger than regular giant ships. The 'Space Bubble' can be used not only as an energy source but also as a tool for searching in different dimensions, meaning that even if you are a dimensional lifeform, it's almost impossible to escape being found.
