I thought that in order to use LN you have to open a channel between two wallets and that this channel is opened with a transaction on the blockchain. So, for example, if I know a shopkeeper who accepts Bitcoin with LN, a channel would have to be opened between him and me, with a transaction on the blockchain, and from then on we could carry out transactions with LN. This, according to the idea I had, would make it convenient to use LN for cases where I know I am going to make repeated payments, but if for example I am travelling and I see a place where they use LN, I would not see the sense of using it for a single payment if a channel has to be opened on the blockchain beforehand.
Though above answer has shared the info, I would like to add a little to make it more easier according to my understanding.
There are nodes which settle payment between two parties. Imagine, there's a popular node which most of the shopkeepers is connected with. It makes sense why would most of the shopkeepers is connected with that node.
If you and your shopkeeper is connected with that node, you can pay him. You don't need to create a lot of channels.
For reference, my topic-
https://bitcointalk.org/index.php?topic=5202798.0As you can see, my topic is a mental shortcut LOL, as I wanted to make it easier for grannies. In technical term, I can be a little wrong but in theory that's what happened actually.
Having used custodial LN wallets like WoS and running several of my own nodes too I can see a need for both.
There are some nodes that no matter what I do, short of opening my own channel to them I can't send them funds.
*Using WoS or Blue Wallet before they shut down worked every time.
Looking at 1ml.com you could see they were only connected to a few smaller nodes and one of the larger ones. So if was tough to find a route, since for a while I only connected to smaller less connected nodes too.
* Once I opened a channel to WoS and a few other larger ones everything worked great, but if I was locking up that much
BTC in a channel I might as well just lock up less and use WoS.
-Dave