Those charts aren't loading on my phone, but I presume you mean Ethereum (not ETH, which is a currency). This announcement says explicitly that the payouts will occur on Polygon, not Ethereum. Polygon currently has much lower fees than Ethereum (though the same scalability bottleneck inherently exists).

hmm, yeah, wow, I kind of assumed USDC transaction costs would be low, but I'm reading they can be kinda steep like eth.