Agree: the PC gaming market size[1] continues to grow and is definitely very very alive.
I am guessing the dead rumour is because the console market is growing faster. Conveniently ignoring that the mobile market is growing faster than the console market (mobile has 50% of market value by some analyses).
Conversely, AAA games are mostly not exclusive to PC keyboard/mouse control (games market could be split by input devices: mobile touchscreen, console controller, PC keyboard + mouse).
PC gaming was never more alive than those last two years.