Could anyone ELI5 the general ideas that Wolfram has been talking about the last few years? I read the (original) announcement post, and the visuals are very i

Could anyone ELI5 the general ideas that Wolfram has been talking about the last few years? I read the (original) announcement post, and the visuals are very interesting and full of neat geometric structures but it's so far over my head I haven't a clue what he's talking about. It's some sort of theory about fundamental structures/relationships that underlie "everything"? How mathematically viable/potentially-legitimate is this? His work doesn't read like a nutjob to me but I also don't have the credibility to judge.