It’s slightly tongue-in-cheek. Web3 is a marketing buzzword for all the crypto stuff.
As I understand it, the idea with “web5” is a properly decentralized network/id system where you can port your account into different platforms.
Ie, an account on nostr can be used to access an infinite number of clients and relays. Anyone can build a client or relay, and any one can participate in the network.
There’s also no useless “token” to scam newbies out of their money for empty promises of future gains.
People just send Bitcoin back and forth here because the Lightning network is amazing 🤙