Why so many constructor calls in priority queue

Question

Hi

Please refer code below:
https://code.sololearn.com/chFgUAA0r5TN

I can understand constructor & destructor calls in terms of set.

Why so many constructors called in case of priority queue?

Answer 1

Question is why after so many constructor calls, people prefer priority queue over set

Set has also first element as highest... Why priority queue