I am not exactly a 'videophile', but, I get discernible results from a cheaper AQ power conditioner with a couple of its outlet filters optimized for video (one of Garth Powell's toys). The TVĀ gets used for some demanding games...gpu ray tracing enabled, etc.
I doubt it makes much of a difference on regular movies & TV shows.
Can a power cord be as useful as such a power conditioner.....highly doubt it!