ChipFlip
$19.05 separates these two used: the PowerColor RX 7600 at $249.95 and the ASUS RTX 4060 Ti at $269. Both are 8GB cards aimed at 1080p and light 1440p. At a gap this narrow, the decision comes down to which software features you'll use rather than which card is faster.
The 4060 Ti wins on raw performance, by a modest margin
Nvidia's card is faster in most rendering workloads, typically by ten to twenty percent depending on the title and resolution. That's real but not transformative. Neither card turns 1440p ultra into a comfortable experience.
DLSS is the actual argument for the 4060 Ti
Frame generation and DLSS upscaling are the reason to pay Nvidia's premium at this tier, and both are more mature than AMD's equivalents. In a supported title, DLSS Quality at 1440p often looks better than native while running considerably faster. FSR has closed distance but hasn't caught up on image stability.
If the games you play support DLSS, the effective performance gap is wider than the benchmark gap.
The RX 7600 is the better card per dollar without upscaling
Strip out the software and you're paying $19 for maybe fifteen percent more performance. That's a fine deal. It's just not a compelling one, and PowerColor's card leaves you $19 for something else in the build.
Both are stuck at 8GB, which is the real ceiling here. Neither manufacturer gave this tier the memory it needed, and that's the thing most likely to age these cards badly.
Bottom line
Pay the $19 for the 4060 Ti if you play modern titles with DLSS support. Take the RX 7600 if your library skews older or competitive, where upscaling matters less and raw frames per dollar is the whole equation.