RE: Building a Lightning Node

The Raspberry Pi is a mini-computer. You could add a keyboard, mouse, and monitor if you wanted. Lightning is a second layer option for Bitcoin so you can make micro payments without paying huge transaction fees. On Lightning, the fees are super small or zero. You don't need a node to use Lightning, all you need is a Wallet, but with a node you have a few benefits. (Alby, Blue Wallet, ZBD, Wallet of Satoshi just to name a few). I started with Alby because it's a browser extension and allowed me to enter the Nostr world too. I saw that ZBD, which I also use because of the games to earn satoshis, has also a way to enter Nostr.
There are a few options to run a node but I thought the small Raspberry doesn't take much space or has a lot of power consumption.

Why should someone run a node?

It's probably the same answer to why someone would start mining BTC. You support and expand the network aka blockchain. With a Lightning node, you need also to run a Bitcoin node and you can connect your BTC and Lightning Wallets directly to your nodes. Basically, you provide a service and use it yourself. It allows you to spend your BTC over Lightning very easily. The Lightning node will earn you a few satoshis depending on the transaction fees between the opened channels.
There are so many more creative ways to earn satoshis with the node or in general. Payback in satoshis for shopping, BTC Pay Server for your shop, playing games on THNDR...

I think I should stop now. The answer got longer than I wanted. 😂

A more detailed answer on Voltage.