Why the huge drop in gas costs?

I am sure everyone has noticed the avg ags cost has droped below 20 gwei since the market correction. Although I am sure the increased gas limit, flashbots and the early L2 solutions (MATIC, Starkware with dydx, etc) have had some effect, the major roll-up solutions of Optimism and Arbitrum are still not in mainstream use. It seems this is most likely due a drop in activity on the network. Thoughts?