they know the collapse is coming, and are now cashing out
Miners have to convert most of their BTC into fiat to pay for their costs, regardless of market conditions.
Therefore for them to make as much money as possible the fees become extremely high.
Miners do not set the fees.
They are the ones choosing to process the highest fees first
They always decide to choose the transactions with the highest fees first - that's how the fee market works. Even when zero-fee transactions were plausible, they always prioritised the transactions with the highest fees. They still can't control the fees.