The Lightning Network was literally the technology needed to enable Bitcoin to be adopted as legal tender at nation-state level. It is integral in Bitcoins evolution as a monetary asset from a store of value to both a medium exchange and unit of account.
Who said this? I don't remember reading about it. Does the government really need LN just to make Bitcoin a legal tender? From what I've seen, they don't seem to care about sidechains at all. At the end of the day, their transaction volume is likely bigger than what those sidechains are made for.