Payouts in L2 Polygon versus Mainnet ?

I'm mining ETH and recently posted about high transaction fees. Someone suggested the Poly trick.

After researching, it recommended using Ethermine and select payouts in L2 Polygon (Matic), so you can then swap coins to something like USDT.

But this doesn't make sense to me because at some point I'd need to convert to USD and it will still be subject to transaction fees right?

Can someone please explain the benefits of using the polygon payout method? If you use this method, what is your strategy?

My goal is to mine ETH and convert to USD every few weeks. What are your suggestions for the best way to do this?