I don't have a cellphone and thus don't know who the king of cellphones is IF there is even such a thing. However, in that same type of Sony fall ... wasn't Nokia the undisputed KING of cellphones for quite a while at one time? At the extreme least, it was definitely a major player, right? And now POOF! Are they even still making cellphones? The last I vaguely heard, they were gonna completely change direction and go into other ventures ... and at a much smaller size of company.
I really hadn't noticed Sony's fall until you mentioned it. And now that you did, it does occurr to me that while Sony was considered the elite of TVs back in the Picture Tube days, now that Flat Screens are the norm, Sony does NOT dominate the space there on the shelves where TVs are on display at stores. Heck, now that I think about it, there probably aren't even any Sony TVs there.
My Stereo system is a small Sony Shelf System. It's been problematic from the word go. My older brother had given it to me because it had been problematic for them since they bought it. It's got a good sound, but it has 3 or so intermittent problems that make me literally SMACK it around to get it to see things my way. :1orglaugh. So, its behavior would not make me want to buy another Sony Stereo.
Then again, the Stereo that I had before that was an Aiwa Shelf System. It had an awesome sound. Loved it! But, it too early on had intermittent CD playing problems. And 2 repairs only worked temporarily. I've just never had good luck with CD Players.