My bro...Web 3.0 has nothing to do with development of Web 4.0 or Web 5.0 You should at least understand that.
Answering the question: Web 3.0 is read, write and own with decentralisation as core emotion with blockchain, DAO, crypto, nft as technologies, focused mostly on the finance sector, gaming sector. And, on a personal point, it is devoured by bigger scams, misuse of trust in blockchain technology, and still follows the digital complexity same as WEB 2.0 (from consumer POV).
All Web 1, Web 2, Web 3 are business-centric approaches while Web 4.0 is the first individual user-centric approach in history.
WEB 4.0 is read, write, own, share, & regulate, a combination of Web 2.0 (development flexibility) with Web 3.0 technologies with user-centric, zero privacy, and human emotion as the centre of core principle. It is a combination of intelligent Web networks (personal network and internet network) to comprehend human emotion, decentralized, semantic, edge computing built on the foundation of AI, ML, NLP, BIG DATA, IOTs personal network, Personalization technology, intelligent protocols, access protocols, open protocols.... accessible by consumers in a simpler, modular and social environment. It can be used for different sectors such as e-commerce, blogging/news, finance, gaming, entertainment (I'm unsure of this one).
It is trying to simplify the current chaotic internet by breaking into respective sectors, building the respective Web ecosystem from scratch using the first principle method,..... for simple, social and seamless access to all people with a hyper-personalized experience.
TBH, it is awesome. Literally shakes the perspective and makes you see the internet as it is. Google the master of the ring by controlling what people discover, keeping stagnant in development, bottleneck growth using SEO as a distributed weapon and made profit by increasing competition in the market. The startup/business failure is directly influenced by Google.