why do expensive amplifiers produce a better soundstage

Thank you to everyone who who took the time to answer my question and Happy New Year!

@dpac996  Thanks for suggesting Doug Self

That was incorrect. Amplifiers have big effect on soundstage. This includes tubes in tube amplifiers. 

There is no such thing.  Price does not play music.  Price does not generate soundstage.  Get real.

Everything in your chain, speaker placement and room matter.

@toddalin 

everyone thinks their system sounds better than anyone else’s.