The alternative to the tower PC is restrictive and locked down consumer garbage;

game consoles: check

smartphones: check

So no, I won't be dumping my tower PCs any time soon.

But what might happen though, is that tower PCs become like the Unix workstations of the 1990s; extremely expensive and only used by professionals and a select few. Microsoft and Google, not to mention the entire content/game/entertainment industry, would absolutely love this. "Use the cloud, subscribe, use the cloud, and subscribe some more!"

You cannot charge people rent when they have terabytes of storage and products that fully function offline, which is what tower systems are all about, and the entire industry is against.