Reminding everyone here, who claims that every user needs to be able to run a full node. Quoting Satoshi Nakamoto:

"The eventual solution will be to not care how big it gets." "But for now, while it’s still small, it’s nice to keep it small so new users can get going faster. When I eventually implement client-only mode, that won’t matter much anymore." "The current system where every user is a network node is not the intended configuration for large scale. That would be like every Usenet user runs their own NNTP server. The design supports letting users just be users."