SmartBCH actually opens up a lot of doors for BCH as a whole. This article is pretty technical, but if this sidechain goes well, it can open up the BCH network into being a "Generation 3" blockchain. (Generation 3 blockchain == a highly scalable blockchain that supports turing complete smart contracts).
ETH is only "Generation 2" because it does not scale well but they support smart contracts.
The smartBCH chain will eventually run into high fees once we get more usage. It's the plight of all EVM based chains, EVEN with the optimizations smartBCH has created for their EVM chain.
More evidence and support for the claim that all EVM chains will eventually become expensive:
https://decrypt.co/87532/ethereum-gas-fees-avalanche-solana
And if Avalanche continues to gather more of the market, you can expect to see many of these same issues moving ahead. Sekniqi has himself also admitted that he doesn’t expect Avalanche “to keep thousands of [transactions per second] at low fees.
https://docs.solana.com/proposals/embedding-move
In practice we see that the most aggressively optimized EVM-based blockchains all seem to peak out around 1,200 TPS
https://www.reddit.com/r/Avax/comments/qzt5nu/insanely_high_gas_fees/
^ avalanche experiencing high gas fees roughly about a month ago.
All EVM chains will eventually become expensive in the future of "Web 3" and the "Metaverse".
So how can smartBCH fix this issue? We can look at other blockchains that have fixed this issue:
Harmony One: Sharding and having three other side chains with Chain 0 becoming a "beacon" chain.
Polkadot: Many Para-chains that all are connected to a beacon chain. The beacon chains doesn't support smart contracts, but serves as a chain that helps communication between different para-chains.
Cardano: "Hydra" that will eventually create state channels ( thinking of lightning network, but better) that will support the same functionality as the main chain but run off the main chain. All transactions in the state channel will eventually settle on the main chain.
ETH 2.0: Sharding the chain and hoping that layer 2s will fix their scaling issues.
Avalanche: Subnets that will run different instances of EVM chains in parallel.
So there's obviously a trend here: I know BCH people believe that everything should be Layer 1, but that's just not going to happen folks, when it comes to smart contracts, especially EVM based smart contracts. The future of scaling are "layer 2s", hell even Algorand is investing in a layer 2.
The EVM has fundamental limits when it comes to vertical scaling, hell even normal centralized applications have difficulty scaling vertically. Which is why normal applications shard their databases and break their applications into micro-services.
How does BCH / smartBCH play into this?
Well if we look at different scaling solutions from different blockchains, there's a design pattern here: having a main chain, that serves as a "beacon chain" the secures all of it's side chains / children chains. Creating this architecture is pretty hard, but smartBCH has created a good framework into making BCH a "generation 3" blockchain.
Because smartBCH works as a pretty nicely integrated sidechain, we can take that same architecture to run as many smartBCH chains in parallel. The UTXO main BCH chain can serve as the beacon chain that secures all of it's side chains and serves as the source of security and truth for all the side chains.
This essentially allows BCH to have a near unlimited scaling capability through horizontal scaling (adding more side chains).
And because BCH believes in having a large block size on layer 1, this allows BCH to support many side chains running in parallel. (Something BTC CAN NEVER DO unless they increase their block size) Also with how smartBCH inherits the security of layer 1, we don't have to worry about layer 1 becoming a "ghost chain".
This is going to be a problem with BTC and their lightning network. They have a fundamental flaw in their game theory, because BTC main chain is so expensive on layer 1, everyone will transact on layer 2. But once all the blocks are mined and their is no block reward, miners would have very little transaction fees to serve as income. Not only that, because BTC can only support such small amount of transactions, miner income is literally capped by the block size.
SmartBCH fixes this because validators for smartBCH are chosen by miners on the main chain. Miners can now have a second form of income because they can choose themselves to become smartBCH validators and earn more income, which incentivizes miners to keep securing the network once there is no block rewards.
If there are many side chains running in parallel because of all the traffic we have and the NEED to shard because of EVM limitations, miners will always be incentivized to secure the network regardless of the lack of block rewards.
All in all, smartBCH lays down a great framework for the future of BCH, and soon we can be able to tell people the transaction throughput of the BCH ecosystem will be near unlimited as we lay the groundwork for more side chains to run on BCH.