If the blockchain can only process 10 tx/s, how will the tx fees be enough to secure the network when all the Bitcoins have been mined?
Especially if we consider the fact that most transactions will likely be off-chain.
Thanks.
This would not be a difficulty change.
Over time technology will make it so it would not be difficult for nodes to handle more TXs per second. Hopefully there will also be an incentive to run a full node (which would increase the incentives to create such technology).
As of now this is not an issue as there are far fewer TXs per second to worry about this.
The first problem is to get people to use Bitcoin enough so that the network has more transactions.