You're missing the keyword 'network'. If you're routing a payment across the lightning network, then it is technically not peer to peer. You send a payment to the next hop in the route, then they send a payment to the following hop, and so on.
As you said, any two parties are able to open (and close) a channel. However, these actions require an on chain transaction, and your funds are locked until you close the channel. Unless you're going to be exchanging many transactions in a short period of time with your peer, you would be better off creating transactions directly on chain.
I won't get into this here, but the lightning 'network' has its own set of scaling problems, which imo are much worse than that of the bitcoin network itself.
As you said, any two parties are able to open (and close) a channel. However, these actions require an on chain transaction, and your funds are locked until you close the channel. Unless you're going to be exchanging many transactions in a short period of time with your peer, you would be better off creating transactions directly on chain.
I won't get into this here, but the lightning 'network' has its own set of scaling problems, which imo are much worse than that of the bitcoin network itself.