Web 3 is not an investment instrument, I think you're confusing Web 3 with crypto
Web 3 is the idea of a new type of Internet which is based on the principles of decentralisation, self governance, tamper proof and trustless
DLT or decentralised distributed ledger is a type of process for revising transactions in a decentralised manner
Blockchain is a type of DLT
Crypto is a token that is used for blockchain transactions
In essence, DLTs are a new base layer tech. The idea is to make things faster and better without the end user realising if they're using a Web 2 or a Web 3 based app. Digiyatra, Digilocker, and several government initiatives are being carried out on the chain now
Because of crypto transferable nature, it is also used as a investment instrument because demand and supply affects its price
I think you're doing the rookie mistake of confusing all of them together