How does that make a difference? As I understood it, every individual would still have to do a regular on-chain transaction, it's only if you later realize you actually wanted to donate more than you did that this could be useful because then you avoid the full transaction fee. Or if you let it run over years without settling and do a yearly donation, though I'm not clear on the implications there.

Or, if the on-chain parties are just Wikipedia and a few big payment service providers to avoid that everyone has to do the setup individually, you've basically reinvented paypal credits or, less evil-ly, liberapay.

I think you misunderstand the Network part of the Lightning Network. It is not necessary for users to have a direct payment channel to Wikimedia in order to donate to them. They just need to have an active channel to anybody in the network who is capable of routing a payment request to Wikimedia's node.

The assumption is that Lightning users already have active open channels to other nodes in the network, and so making a new donation to Wikimedia would not require any additional channel opening, and no on-chain activity.

Thanks for clarifying that! Now that you mention it, I remember reading that but forgot it again somehow. That does (positively) change how well this can work without compromising the whole idea behind bitcoin.