Because 21 sats is well below the dust limit. I should have added if your ln wallet is self custodial. I guess with custodians itβs no problem. What are you using?
Discussion
What you say would be true if you would have 1 million ln channels with very low funding which by the way you couldn't even open. As I understand one ln channel corresponds to one utxo onchain so withdrawal is possible as long as the channels are big enough.
I need someone to explain this to me so I can understand.
Let's say 10 people send me 21 sats each, and they all come through the same channel. Is that only one UTXO to enforce? How? I don't get it.
A channel must be funded in order to open it. That's one onchain utxo. It is probably some kind of multisig magicwhen you use self custodial but not self hosted ln wallet. I don't get this completely either but ok. π
Depending how much you funded the channel you'll have inbound and outbound capacity, so as long as you transact within this range nothing happens onchain only when you close the channel - to withdraw you funds - you deal with utxos again. The same with the ten people who want to send you 21 sats they also have channels funded etc. etc.
Only channel open and close happen onchain, the zappening in between is only on lightning nothing to do with utxos.
I have blindspots too but I hope it helps a little.
So if those 10 times 21 sats arrive at my ln wallet through the same channel itβs just one UTXO for me to enforce?
What do you mean by enforcing an utxo? Maybe I misinterpret your question.
One utxo to open a channel and another one to close it. What happens in between on LN has nothing to do with mainnet, just like opendime. We can exchange as many opendimes as many times we like until we spend it doesn't require any utxos. Probably not the best example, the usual one is the concept of bar tabs.
Probably itβs the wrong term. By enforcing I mean going on-chain. So closing the channel/s.