It will still have some state, things like merkle roots will still be verifiable, and any derived/state that isn't kept from the main chain will have some form of proof that links it to the main chain.

Most actual transactions/normal user stuff is moving to layer 2 chains, which commit a hash or proof of their state to the main chain. So they will still carry their state, but rely on the security of Ethereum main net.

There will still be archive nodes that store everything that's ever happened, but being a full archive node won't be required to run a normal node as a validator or as a user. This allows the network to be more decentralized without every node needing 2-4TB of fast nvme to even do anything.