What GPU upgrade makes sense for my older i5-9400F gaming PC?

I wouldn’t buy a GPU specifically for GTA 6 yet. The PC version may arrive considerably later than the console release, and both hardware requirements and GPU prices could change by then. If your current RTX 2060 is still handling your games, waiting is probably the safest option. If you need an upgrade now, choose based on the games and resolution you currently play rather than an unreleased title.

Your motherboard can support a ninth-generation CPU such as an i7-9700K or i9-9900K, although used prices can make that upgrade poor value. The i5-9400F will bottleneck faster GPUs in some games, especially at 1080p and high refresh rates, but the bottleneck becomes less noticeable at 1440p. A used RTX 4070 could be a strong choice if the price is good, though you should budget for a PSU upgrade first.

For gaming value, don’t limit yourself to Nvidia. Comparable AMD cards can offer more performance or VRAM for the money, especially on the used market. If you prefer Nvidia features or efficiency, a 4060 or 5060 should be manageable, but I wouldn’t pay a lot for an 8GB card if you’re specifically planning around a demanding future game.

Before choosing a card, I’d replace or at least closely inspect that 500W PSU. If it’s already seven years old or from a questionable product line, it’s not something I’d pair with a high-end used GPU. A quality 650W unit would give you much more flexibility. Also check which PCIe power connectors it has; cards above the RTX 4060-class often need more power.