Polish deputy prime minister says otherwise:

By asking Poland to shoot down Russian missiles over Ukraine, President Volodymyr Zelensky is attempting to get Warsaw involved in the war, Polish Deputy Prime Minister Krzysztof Gawkowski said in an interview with Radio ZET on Nov. 4. https://kyivindependent.com/zelensky-wants-to-drag-poland-into-war-with-russia-polish-deputy-pm-claims/

It’s a choice by the Polish.

There is also the issue of

1. Batteries protecting major cities.

2. Munitions being limited.

3. What can be shot down depends on the altitude. See point 1.