Web 2.0 has already come and gone years ago.
I think of Web 2.0 as akin to visual looks. Shiny glassy buttons and reflective textures and transparent elements. The rise of flat design and Google Material kind of ended the Web 2.0 look and feel.
Web 2.0 was also the rise of two-way communication. More social networking, comment feeds and forums, user driven content. We saw the rise of specialized websites, ecommerce explosion, and the ability for anyone to get a basic website online becoming super cheap, thus the rise of personal brands, blogs, fan sites.
If you think of Web 1.0 as basically certain companies disseminating static content down from on high, you can think of Web 2.0 as as a big party on the Internet and everyone is invited.
Web 3.0 which we've lived in for years focused on standardization of concepts, modularity, reactivity, big data, SaaS, PaaS, DIY, virtualization, adaptability, responsiveness, etc
Just my random 10k view of it.