It is based on information available on the internet, in case you haven't read enough about the topic, it would be great if you read more about governments interested in using blockchain.
You shouldn't believe everything you read in the internet.
There are much better blockchain than bitcoin these days, not sure what source of news you reading, if you refer to btc, yes it is slow but not for a long time, LN is here to solve that issue. It might be expensive if a centralized organization will implement their own blockchain, but if they use or support existing ones then they don't have to spend resources owning all nodes, there is where decentralization takes place when individuals run their own blockchain node.
I don't like to discuss about this topic... but I will try to be dry.
First of all, of there is a "better" blockchain, why bitcoins is the most valuable one? Think about it.
And no, lightning network has nothing to do with blockchain. It is an off chain solution. Do you know why it is called that? Because it is off the blockchain.
Private blockchains may be a thing in the future, but they are not now and there is no indication that they will be used by governments in a near future.