Poland is a problem for the EU precisely because it will not leave

I don't think Poland is a problem. The EU has to focus on not becoming the problem itself. Contrary to popular belief there are democratic deficits that haven't been adressed and that includes the CJEU which in its current form cannot really be impartial in my opinion as long as it doesn't focus on keeping contractual obligations. So it is quite ironic that the accusation from CJEU is about impartiality of judges in Poland. There are issue there, out of the question, but so there are on the EU level. So much so that any antagonistic system of justice is welcomed.