Why not do the docking instead of EIP1559

From what I’ve heard it’s planned to dock mainnet with ETH2 earlier than expected, but still only in a year or so. Why are they doing EIP1559 before that, keeping the risk of miners opposing it?

It should be possible to dock rather soon, right? Even if it was 1-2 months later than the planned EIP1559 hard fork date, it would reduce all the debates and just get rid of PoW quickly. So why are we still waiting to do the docking? Is it so hard to complete technically?