With bitcoin you can send funds peer to peer. No trusted intermediaries. Routing through a network of exchanges is more like routing through SWIFT or ACH.
For a large fee and with a lot of uncertainty on if it will make it into a block. Try the fork of Bitcoin that still operates like Bitcoin used to up until 2016: Bitcoin Cash.
Bitcoin cash is just another alt coin at this point. Transactions have been dwindling and it hasn't even had a reason to flex it's larger block size yet (which is why it was created).
If a payment channel is still open, then the blockchain hasn't confirmed anything yet, the only speedup is to reduce roundtrips to the blockchain in the case of a series of transactions. So you are still limited by the speed of the blockchain, unless you decide to trust parties in the Lightning Network.
You seem to dislike lightning network, but the reason given are not accurate.
What would happen if there was collusion between nodes?
And while it is true that you are still limited by the Blockchain speed if the nodes don't cooperate, all the incentives are made so they do cooperate and that transactions happen near instantly.