The point of cash is that it represents transferrable value that doesn't require an intermediary between you and the person you're transacting with. And yet, banks and credit card companies exist and deal with cash. This does not mean that cash is a useless concept.
That credit cards exist didn't mean cash stopped existing. Likewise, just because CEXes and L2s exist doesn't mean L1 cryptocurrency doesn't exist. You can still grab a non-custodial wallet and still manage your own crypto. Today Coinbase has a debit card that can sell crypto at FMV, apply their spread (1.88% I think?), and immediately use that to pay off USD denominated bills. So if your crypto is in your wallet you can just send your Coinbase wallet the funds for the purchase and then swipe your debit card to pay.
Coinbase's spread isn't the worst thing to pay for the service of having a debit card and auto-selling, but if you also buy crypto using Coinbase, they double-dip on the fee.
Okay and the key difference between crypto and cash/credit/whatever is supposedly that it is decentralized. Or have we abandoned that false premise now?