It was a great idea to make our blocks change size with demand, that way our money network can remain lean and cheap to run during times of less use, and quick and useful when it becomes popular. But remember that our money works because of a delicate balance of incentives. If those interests get out of whack, someone is gonna attack or profit from the other, or both. If someone can do that, people won’t trust it, and our money would die.
If miners profit from the fees that users pay to get their transactions written in the money ledger, they would have an incentive to make the blocks as big as possible. Bigger blocks, more transactions, more fees, more money. But if they do it quick, a miner could make a gigantic block and mess the whole thing up. To avoid that, we’re not only making the size of the block dynamic, but also the fees received. If there are more transactions pending, the price to get them written on blocks shrinks. That way, the income of miners doesn’t suffer, it’s predictable, and the network is not spammed.
What do I mean by spam? Just like email spam, if we make transactions free or almost free, it would be very cheap for an attacker to just make millions of transactions to clog up the network for the real users. If a government doesn’t like our money (probably because it’s better than theirs) we should add a mechanism so that any big player trying to use our money too much, instead of hurting us, help us.
With this design, miners can’t abuse the fee system, node operators won’t see their copies grow uncontrollably, users will see their transactions confirmed quickly, and if someone tries to spam the system, it’s just as good as if the system became more popular. More fees for miners, more miners for the network, more decoys to pick from, and why not, more publicity.