Right now Web2 is a steaming pile of garbage.
Everything is contained in giant, centralized websites that are completely closed off from everything else, with the website owner completely in control of everything on its servers. You go to Google in order to do Google stuff the way that Google intends you to do, whether you like it or not, you have no choice on the matter. You liked that feature? Too bad, now it's gone, because our internal tests found out that our conversion rate raised by 0.001% by removing it. And here, enjoy your new bloated, overdesigned UI with ads everywhere. No, you can't switch to the old one. Also, your data is actually Google's, so they can decide that they don't like you and just outright delete it, or sell it, or god knows whatever else. This applies to essentially every single website that you use, because the data resides on the website's servers, whose security and management is up to the website's owner, simply because up until now it wasn't possible to do otherwise.
Enter Web3. Now data resides on the blockchain, and websites access and manage that data in a completely decentralized manner. Take Uniswap for example. If for any reason they decide to shut down their websites because the owner's voodoo advisor told him to shut it down or his mother would die in her sleep tonight, people would still be able to use it by simply hosting a Uniswap interface on another server. The data is still there, on the blockchain, completely secured. If you wanted you could also build your own website instead of using the official one. Up until now that simply wasn't possible. Yes, you could use their APIs, but even then you would be subject to the limitations imposed by the API providers.
This is a complete paradigm shift from what we had up until now. It completely solves a lot of problems that we have been facing in the last decade because of the complete monopoly of Google, Facebook and the like.
We're going to take back the web.