If you had a choice between a block size increase (soft or hard fork) and a drivechain, which would you choose? Why?
On the block size increase, none for now, and on Drivechain, clearly you know my answer is "I don't know", I'm still learning about it the hard way. By debating/playing devil's advocate.
Let me ask that question a different way.
What do you hope to achieve by forking a drivechain into the consensus? Offloading transaction throughput from the mainchain, cheaper fees? Altcoin interoperability?
I think economically important drivechains may skew Bitcoin's mining incentives. I'm not sure. I'd like to see more convincing game theory suggesting drivechains are a good idea before considering enforcing them at the consensus level, that much is certain.
Why? Mining on the base layer could be worth more because it supports all side-chains. Plus if a side-chain has value, wouldn't the game-theory/incentive-structure be the same as in Bitcoin?
I was thinking about this a bit more.
Consider this situation presented by Adam Back, except let's take it to the logical extreme. Say we're a couple decades down the road, the block subsidy is tiny and fees provide almost all block rewards. Mining has a 5% profit margin and drivechains provide 75% of total revenue.
This implies a super majority of transaction activity -- and probably a majority of bitcoin-denominated value -- is on drivechains.
Meanwhile, a majority of miners can steal all funds held on drivechains at any time. There is nothing Bitcoin full nodes can do to stop them.
Is the incentive structure still the same as now?