The days of captain's "running the show" Captain Bligh style are thankfully long gone from Airline operations. Modern CRM demands it...and safety outcomes are the winner for it.
Both the Captain and the FO are integral pieces in the system that gets an aircraft safely from one place to another. Their parts are clearly and definitively scripted by the Company.
The Company explicitly tells them both what to do and how to do it.
This includes ensuring that both pilots remain current.
Unless there is a sound reason otherwise (such as inexperience, or pilot performance issues into a particularly challenging airport) , then the Company REQUIRES that captains share PF duties with First Officers.
Behaviour otherwise will quickly find that Captain having to explain themselves to the Company. For it is not the Captain's train set...it is the Company's.
While friendly respect for the Captain's position should be a given, grovelling FO thank you's for being 'allowed' a PF leg are not required.
The captain may be the PIC...but The Boss is ALWAYS the Company!
PG