When the check comes but they don't take litecoin
On the (block)chain... is the new off the chain. Over the past year, bitcoin has ~9X'd in value as corporate and retail investors have poured into crypto. In January, the crypto market hit $1T in total value (mostly bitcoin). Now, the mainstream-ification is intensifying: Venmo-owner PayPal, which has a whopping 377M active accounts, is embracing the crypto life.
Paying with crypto... but not really paying with crypto. Customers' crypto holdings will be converted into fiat currencies (like US dollars) at checkout. It's kind of like selling a fraction of your BTC, then using the sale money to buy a rice cooker. Merchants don't actually get paid in crypto — and that's way safer for them, since crypto is so volatile.
BTC is still mostly viewed as a speculative investment (not a currency)... It's too volatile for most to use it as currency, which is why PayPal is converting it (and why Visa is only allowing a stablecoin). It's also why Tesla — which now lets people directly buy cars with actual bitcoin — has instituted a 30-minute purchase window. Given BTC's surge this year, some investors also see more potential upside in holding on to it rather than using it for purchases. But as we've seen in the past (see: 2018), bitcoin has a big potential downside, too.