Are blind people not intelligent? Is it actually important to have a full understanding of the world? What about people that grew up in isolation? I think there are still some tribes in the Amazon that have had little or no contact with modern civilization. Are these people not intelligent?

There are some deep philosophical topics lurking here. But the bottom line is that you can obviously have intelligent conversations with blind people. Doing that with a person that is both deaf and blind is a bit challenging, for obvious reasons. But if they otherwise have a normal brain you might be able to learn to communicate with them in some way and they might be able to be observed doing things that are smart/intelligent. And some people that are deaf and blind actually manage to learn to write and speak. And there have been a few cases of people like that getting academic degrees. Clearly sight and hearing are not that essential to intelligence. Having some way to communicate via touch or something else is probably helpful for communicating and sharing information. But just a simple chat might be all that's needed for an AGI.