IOHK2 currently has 208 million staked to it. The current saturation point is 1%, which is 90 million. By delegating to IOHK2, your rewards are 50% of what they could be.
My guess for why ADAPL is not 50% more is likely because they missed a few blocks here and there whereas IOHK2 was more stable.
Long story short: You should redelegate your stake from IOHK2 to another pool.
///
I think a common misconception is that a smaller pool won’t provide the same rewards.This is untrue.
A smaller pool, as long as it remains efficient (meaning it makes the blocks it is given), will provide a similar reward, if the fees are the same. The only difference is that the larger pool will give more consistent (albeit smaller) rewards. The smaller pool will give rewards in more sporadic “chunks”. The smaller the pool, the more sporadic the chunks.
For example, let’s say you have 1000 ADA delegated across 10 epochs.
In a large pool, you may get 5 ADA each epoch.
Example: 5, 5, 5, 5, 5, 5, 5, 5, 5, 5 = 50 ADA
In a smaller pool, you may get larger “chunks” of ADA and not get rewards every epoch.
Example: 0, 0, 0, 10, 15, 0, 5, 20, 10, 0 = 50 ADA
See this post for more information: