Usually PC Gamers buy the games first, and then if they are not satisfied with their current GPU's performance, they might upgrade - maybe... or lower the settings a little. Unlike console gamers - pc gamers have a lot of adjustability at their disposal.

Anecdotally, most PC gamers I know unintentionally go in 2-3 year cycles for upgrades - usually the GPU. It's not planned, it's just when things start feeling underperforming. Often after upgrades, people binge old games they already owned but now at higher settings or FPS.