I honestly can't categorize this question to neither black or white. It's a misleading question that is interpreted differently by each individual. You're asking if LN is Bitcoin. In which terms? Network-wise? Of course they are not the same. Consensus-wise? Of course they are not the same. However, if I use Lightning I do use Bitcoin. The currency is the same. The way that transactions are accomplished is changed.
Yes, they're separate networks obviously, but they do the same thing. They allow you to transact bitcoins. The transaction structure and the contracts are different, but the purpose remains same.
so are you saying that in YOUR 'fact' (opinion) the currency inside LN payments is the same?
.. and now we full circle back to Msat discussion. and the 1:1000 peg.
are you sure LN transacts "bitcoin". even though "bitcoin" never leaves the blockchain and the pegged "bitcoin" you speak of does not transact until its confirmed to have transacted on the bitcoin network.
now before replying. do not confuse the locked funding or the not on blockchain "commitment" with the "LN payment" of messages denominated in msat.
do not try to say lightning only handles sat measured bitcoin 'payments' by discussing commitments that are never sent around hop/routes of the LN network, just to ignore the msat payment stuff that is sent around the LN network.
i played that game with rath_ already and it didnt work