It's rather simple, within a mere decade, given the current scale of Human Civilization, even if there is progress, the room for improvement won't be substantially large.
Moreover, this also means that the time borrowed from the future Legion cannot be too long.
Because it needs to be returned afterward.
A mere ten years is not enough to completely eliminate the crisis; if the borrowed time is too long, it would result in a significant period in the future lacking enough power.
It sounds like it can only be used in some key battles?
That might not necessarily be the case.
After all, the entirety of Human Civilization is currently under the protection of Shen Hao; from this perspective, a period of contraction wouldn't necessarily lead to a great crisis.
On the contrary, if a strong push can be provided before the initial momentum has built up, it could still have a significant effect.
