I believe that the whole debate is trying to engineer what should be a market based solution.
We already know everything we need to know to fix problems concerning the Calculation Problem and the Tragedy of the Commons.
Either the resources in question need to have clear owners or the the resource needs to be not scarce.
So what about Block Size?
Well, either the block size needs to be owned by an entrepreneur or there must be an infinite block space available.
Any other solution creates an arbitrary floor or ceiling which will inevitably mean surplus or shortage, except only coincidentally.
So we have our choices.
1.) The block size will be managed and owned by an entrepreneur.
2.) someone needs to invent a way to make block space not scarce, which is intuitively impossible.
3.) Make some non-market based decision about the block size, which will be consistently incorrect over time.
2 is the only way to solve the problem without giving up decentralised control of the currency, which is why things like Segregated Witness, and the Lightning Network are so great, but ultimately I doubt enough technology like this will ne invented to make block space not scarce.
3 has always been outcompeted by 1.
So that leaves us with our answer. Ultimately the block size will be decided by entrepreneurs via competing configurations in the market.
So try to pick a block size that is bigger than your competition, and provide it at a better price.
Unfortunately, I believe that will mean cryptocurrencies will end up being highly centralised. The good news is that free markets themselves are decentralised.