That's simply because in games, the CPU is not nearly at such a load level and thus power consumption as it would be for example in Cinebench R23. This goes back a bit to the post i linked
here.
With different load, you have different power consumption. So in games, your GPU is far more loaded than your CPU, but obviously the CPU still has some influence on the overall performance. Since the CPU doesn't run into the power limit (which seems to still be active in your BIOS), because the load is less demanding in games, it can actually clock higher and your OC can achieve something. However, with more demanding load, such as encoding, rendering, in short, any real full multi-core CPU load, the CPU hits the ceiling of the power limit, which also restricts the performance. So once you fully load your CPU in a more demanding way than in games, your CPU performance might very well drop below the level you could have achieved by simply removing the power limits in the BIOS and not overclocking at all. That's what i meant with "it would basically be for nothing".
So if you want your OC to truly be effective with any kind of load, no matter how demanding, you'd have to max out the power limits. They are found on this page:
Short and Long Duration 4096W, Current Limit 256A, or by selecting "Water Cooler" here:
But while you're now still seeing under 90°C with a mere 220W due to the power limits, prepare for your cooling to be utterly overwhelmed then. This is the true consequence of such overclocking.
And by no means would i advise this with your CPU, because the efficiency goes to hell, even if you could cool it.
If all of my assumptions are correct (and they aren't always, i will freely admit that), then you have essentially overclocked for less demanding scenarios only, and with more demanding scenarios you might even lose performance, compared to just maxing out the power limits without any OC whatsoever.