Also applies to the routing amounts. Nobody can tell you which amounts are forwarded and which aren't, unless node operators make it public. Spoiler: Most node operators don't do that.
Does anyone believe that messengers are confidential, just because they will not share their information with anyone?
What I'm saying is, that node operators only know about the routings of their own node. They don't know the origin and they don't know the destination of a transaction unless they started it themselve. Most of the node operators are completely unknown btw. So if somebody shares the info about the tx he was routing and how much fee he earned, you still don't know anything about the other nodes and you might never find out. Everybody is free to tell you how much Bitcoin he has, still many people won't tell you.
And this is a true statement. From this statement another true statement follows:
If node operators make their data public, then everything will be bad with privacy in LN.
No one can guarantee that node operators will not do this. You can only believe in it. But, as the English proverb says, "When three know it, all know it".