With a regular cryptocurrency they could just post an address or QR code and anyone can send it using a wallet at any time (no need for them to be online or anything).
Lightning allows single sats worth of micro-payments in real-time, perfect for tossing a few bucks someone's way vs. paying much higher fees and waiting for blocks.
The Podcasting 2.0 spec also includes the "Boostgrams" feature allowing you to send messages to the creator with your payment.
Speaking of offline support the recently announced Hedgehog protocol builds off of lightning and is much more asynchronous.
