The dumb sidechain argument that BTC uses.

You know that BTC maxis always talk about lighthing network as a solution to the scaling problem, but it's just BS, and i will not even use math or others complex concepts, to keep it simple:

What you need to open a LN channel? You need of a relay node to be online, that's not the problem, the problem is that to open and close a channel you need to do a on chain transaction, wich basically kills the purpose of LN, you need to pay $20 fees to open the channel and do a transaction, and more $20 to close it, it would be much easier to just do a on chain transaction, the cost only is worth if you are doing a lot of transactions in short period of time.

Now imagine that BTC becomes a global currency, and 600 millions of people want to open a LN channel and never close them (being very generous), at the theorical limit of 7 tx/s, it would take 3.1 years to these transactions be confirmed (assuming nobody is using the on chain for other purpose.)

So if the on-chain of a cryptocurrency is slow, a side chain can't fix this, that's why Ethereum is changing the on-chain to improve scalability, not implementing a side chain to do it.

Side chains are supposed to remove large things of the blockchain that are not essential, like what is happening with BCH, smartBCH will be a side chain for smart contracts, so the on-chain only needs to take carry of transactions, carry essential things in a side chain is just dumb.

Basically with smartBCH, BCH will be a good payment system, store of value and smart contract plataform, all using the reliable PoW, that's much more efficient than the PoW of BTC due to bigger blocks, and more secure than the PoS that Ethereum will implement, due to a 51% attack being more expensive.