Maybe the positivists’ antipositivism should just be “not everything demands an empirical explanation in order for us to continue functioning well in day-to-day life, and that’s just fine.”

> what is its alternative?

Accepting that we won’t know everything (but also accept that there are things we don’t know yet and that will be known in the future, and that it’s ok to change your mind in the face of new evidence).

Actually, it’s not really an alternative to empiricism, but I don’t thing that empiricism has this particular weakness.