you are missing the complete point

much like many thought that LN was soo utopia that there was no way to fractional reserve because all channels had locked and confirmed value.....
.....
until thor turbo proved it was possible and people were getting inbound Msats not backed by a confirmed bitcoin 'funding lock' utxo

when you realise that there is also no network consensus and that msats are not 1:1 rated with sats.. that 1:1000 ratio can be messed with too


where when compiled, and a service tells people to use their app.. people wont know of the rate change while using LN.. they see the msats and dilly dally happily moving msats in onion payments
.until.. they broadcast the commitment and see onchain that they are getting not as much as promised..

then you will see

now try and tell me.. what network wide mechanism ensures that msats are always going to be a 1:1000 rate

much like what network wide consensus made sure all channels had a funding lock utxo

i assure you there are many flaws that can be abused in LN. and you seem to utopian dream to observe them