I enjoy devils advocate, but the only thing you said that is true is that btc is battle tested. Whether or not it is as secure as dpos, is a squash. Both have a balanced ledger and as far as trust goes, anyone who uses steem or btc understands both are truth worthy. People just know one more than the other.

As for the lightning network, it's suppose to reduce traffic and reduce fees, but it's still not fee less and it will never overcome the speed of steem for finalizing transactions. It's intent is to have off blockchain transactions using side chains, so you still have 10minute confirmations times once you are back in the chain.