2 failed megaprojects so far, diem and the metaverse. Aim small miss small. Fail fast, fail often. Don't wait until you spent billion of dollars over half a decade.
If you're asking the wrong questions, the answers are going to be pointless no matter how much time or money is invested.
The problem for Meta is all of the questions asked were never congruent with reality and organizationally there's no incentive to work on coherent ideas because of politics. These layoffs are not a surprise to any realist.