REG2012: I always turn off vsync. It isn't needed anymore. In fact it hasn't been needed for at least a decade lol. Who wants to limit their refresh rate? It's completely unnecessary.
Jus to clear this, even if the message is old, if you are using g-sync or freesync you better turn on the vsync.
If you're using g-sync or freesync, it is to get rid of the tearing effect. If you leave v-sync off, that means your frame rate can exceed your monitor spec, and tearing will be back.
Yes, for the time being most of the players won't reach higher fps than their monitor refresh rate (i doubt anyone use a 60Hz monitor with a beast like a 3080/3090). But it is still useful and with DLSS like feature, it will be more and more useful for some players.