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.
Just to show you the problem: Try to contact this node with a liquidity of more than 7 BTC 02fb22354383c240f9a04b194d610186cdec1045d961cb7989f254cb7c96498ab5@opwodusf33oapzmpg7nmtpjtdpauaa2m6ym2y6yvm7t2ju34x4jmctqd.onion:9735 and find out how much routings he has and how much fee he earns. If you achieved this (which I doubt you will), you still don't know much, because he can lie to you and also he doesnt know about origins and destinations of the txs he routed.