How Can Component Video look better than HDMI?

So, I just returned from my In-Laws after a week. I went to their basement TV to watch and was blown away by how clear that picture was. To my surprise, Their 6-year old Samsung TV and their ancient Scientific Atlantic HD cable box were hooked up via component video cables! When I got home, I dug out my old component cables and hooked my RNG150 to my 3-year old Samsung TV and it looked the same as HDMI (and not as good as his.) I am baffled. How can this be? Notes… his TV connects component video by RCA female jacks while mine uses RCA-to-1/8” plug adapters. His cable system is Spectrum. I double checked all my settings to get the best possible picture but it does not look as good as his. It’s hard to describe but it’s kinda like when you watch in 3D – things in the foreground have a definitive depth from the background on his TV. Is this a case of simply older gear being built better than the new stuff? Any ideas / suggestions?