Everybody has a PC because they needed it to communicate with the outside or for work or for school etc. Telephones and tablets replaced that solution. So that market dissapeared for PC.
When digital store front wasn't a thing on PC, most devs jumped over towards consoles because single player department of gaming was dead on PC. PC moved towards online multiplayer games and most of these company's where stuck in there old ways and didn't wanted to shift over but instead keep making the same shitty single player games nobody cared for anybody on PC. And the ones that did care where hit by piracy heavily.
Also company's like sony and nintendo started to heavily invest into developers to bribe there titles ( microsoft also ) towards there platform in order to set it apart and make it sell which killed of this market entirely for PC or mostly. Digital shops however reversed this in the recent decade again.
PC gets pretty much all the single player games now, but also has a huge own library of games that all revolve around competition and online solutions. The biggest titles of the last decade are all PC titles and dwarf the console user base massively.
So...how did I contradict anything you just said? If anything, you are the one writing some bs things. The PC wasn't needed to communicate with the outside. When proper internet speed became a thing, so became mobile phones (not to mention normal phones before that). The PC was just an option. It's still used for work and school. That hasn't changed. Tablets got added as an option. However, as I said before, kids prefer to play on smartphones instead of PCs...heck, not even kids alone. Lots of adults switched away from PC to smartphone gaming as well.
It wasn't dead, it got reduced due to the MMO craze and publishers putting tons of awful DRM in place (I've written about that before in this forum). However, people playing MMOs like World of Warcraft doesn't mean that they didn't play on the PC. So that rather confirms what I said.
The rest you write is not relevant. The PC gets a lot of the singleplayer games...just like before in relation to consoles, starting with the PS2 and XBOX when multiplatform games really became a thing. Obviously, in the following generations consoles just became more and more similar. Also, the number of titles released has nothing to do with PC gaming being more relevant in Europe today than it was over 10 years ago. "The biggest titles of the last decade are all PC titles and dwarf the console user base massively." Lol, so did the biggest titles of the last two decades. There is no point in that sentence because it's a.) stupid and b.) not relevant.