When discussing block size, one question is what the potential downside of each solution is.
The existing limit was introduced in 2010 to deal with the scenario of a malicious miner building an oversized block to damage the network. At the time, there was no danger of legitimate use cases testing that limit.
Six years later, Bitcoin has grown massively and this limit actually starts damaging legitimate use cases. That’s a good problem to have, since it only exists because of the success Bitcoin had in attracting users.
But it is a problem that requires a solution.
In this debate, one side (those calling for larger limits) can point to clear and present damage. The blocksize limits mean a cap on the number of transactions right now. They mean that it makes less sense to invest in the space, since in contrast to the past you can’t expect growth to continue until this problem is solved.
The other side can only point to hypothetical and future damage. They can only speculate what would happen under a 2 MB or larger limit. And any possible downside is necessarily in the future as long as bigger blocks are not yet allowed.
As far as I know, there is no minimum block size and no one proposes to introduce one. Even if the maximum is increased, miners would still be free to keep working with a lower maximum, if for one reason or other they want to.
While it is clear that any possible downside from increasing the limit is both hypothetical and in the future, what exactly is that downside? Is it potentially so devastating that keeping it from happening is worth having a cap on the number of transactions kicking in this year?
(This post is also published at the Reddit “btc” forum).