The advantages of the newest mouse, keyboard and headset are greatly exaggerated. You quickly hit very diminishing returns when it comes to gamer mice and keyboards, and a headset certainly doesn't need a lot of fancy features to be good enough.

You're basically paying for bling and features that don't really help the actual game for headsets. Even my "gaming headset" that cost over 200 dollars doesn't outperform a 50 dollar gaming headset at actual gaming. It's just that it delivers the same performance while being wireless, and having fancy features like multi-input which is useless while you play anyway, and glowing lights.

As for a 120hz display, you can get one with freesync relatively cheap, and it's not like you need a new one for each new console generation. Displays last a lot longer than other components, except maybe your PSU, and retain their value for way longer than other components if you want to sell them.

Still, it's not the same because while PC gamers knew they signed up for this, console gamers did not sign up for this but are now forced to deal with hardware upgrades probably 40% more often than before.