Ethereum co-founder Vitalik Buterin has revisited the discussion on layer-3 scaling solutions in the cryptocurrency community. He emphasized that while these solutions don't inherently improve throughput, they can be used for cost saving. Additionally, he highlighted three main visions for layer-3s, including customized functionality for different use cases, customized scaling, and weakly-trusted scaling in the form of validiums. This ongoing discourse reflects the evolving landscape of scaling solutions within the cryptocurrency space.