There are a lot of problems for which you can create solutions that involve web3 and blockchain but that doesn't mean that technology is necessary nor sufficient to solve those problems, nor that it is the best solution (or a good solution, at least).

Web3 and blockchain do solve a number of problems in the specific scenario that you want to collaborate within domains controlled by the blockchain with individuals you actively distrust, though. With the obvious caveats that you have to trust the blockchain itself (which both in PoS and PoW means trusting people with sufficient wealth to control large portions of the infrastructure) and that everything you want to do has to be within domains controlled by the blockchain (whether the actual problems within that domain benefit from this or not).

So in a sense the question becomes how much you are willing to sacrifice to be able to solve that class of problems instead of redefining the problem so it doesn't require a blockchain.