As far as i understand web3 (not an expert) it is a bit more nuanced than many comments. A short historie irrc web1 was just websites and hyperlinks so early web. Web2 is where we are mostly jet. High centeralisation, few have power over the whole internet landscape (FANG, etc). It is built around closed systems and users as well as content creators are hostages of these services. Web3 means a new decentralized Web. It is supposed to be more democratic, because everyone can contribute and everyone has the same amount of control. A example for that is the fedivers the place you are in right now. Or I think P2P nets like Briar and I2P belong also in this category. But also crypto. Which don't get me wrong can have valid use cases in a world still relying on currencies. But this idea was hijacked by the hyper capitalistic techbro scene. Which also calls them self "libertarian" and has the slogan "don't tread on me" and "become ungovernable" but has few in common with actual Anarchist thought. And therefore is not compatible with the Anticapitalist as well as the post-hierarchical stand of Solarpunk. An example is the abuse of crypto mining to create money out of thin air while reducing the decentralization aspect. And also NFTs.

tl;dr: in my eyes web3 is Solarpunk but it was like many ideas infested with hyper-capitalist ideology.