In most debates about BCH vs. BTC, the concern expressed about BCH and increased block sizes is that it will make running a node very expensive.
Critics point to the number of transactions that Visa processes and say that would require ~8GB blocks.
In this utopian scenario—utopian because BCH would be processing Visa level transaction #’s—the problem that arises is the cost of running a full node would price out regular users.
If there are only big players running full nodes, it would be possible for changes to be made to the code—for example changes in the inflation schedule—and no one would notice because there are so few or no honest nodes.
The pace of technological development will mitigate some of the cost of running a node, but even if the cost of nodes did rise to a level where it is completely unaffordable for an average user, a much simpler solution would arise because of the clear incentive for watchdog organizations.
If BCH adoption is rapid and the block size grows faster than technological growth that means there is a massive amount of value that is stored on the BCH network.
There will be millions of honest users with an incentive to protect the value on the network.
There will be tens or hundreds of thousands of businesses with an incentive to protect the value on the network.
There will be thousands or tens of thousands of miners with an incentive to protect the value on the network.
For businesses and mining pools it would make economic sense to finance and run their own nodes. But they would also have a massive incentive to finance watchdog organizations that run nodes and serve an independent watchdog function, like a bitcoin cash Nights Watch.
The same is true of the day to day users. If hundreds of billions of dollars of value are stored on the network, the costs to finance a watchdog organization that runs nodes is a drop in the bucket.
This organization could be set up as a non-profit, run nodes, mine, and employee people to metaphorically stand guard for the network. They would create a lot of value and be rewarded well for increasing trust on the network.
Unlike the Game of Thrones Nights Watch, they would not need supplies and budget to maintain a giant wall and protect a massive army of undead. For a relatively small cost, they could greatly increase trust in the network.
BTC is crippling it’s network to protect against a hypothecal problem in the future that would be solved first of all by the economic incentives of big players on the network and improvements in technology in the future. But even if those did not create enough trust in the network there would be a massive incentive for the creation of independent organizations that run nodes, increase trust, and secure the network.