To be frank, the value proposition of those investments was never what the companies claimed they did but how much money they could bring in before going bust. And of course some of those companies were also useful by fostering acceptance of ideas those investors benefit from: for example, a big part of the "blockchain" and "smart contracts" narrative was privatization (or "democratization") of government functions (e.g. managing land deeds, educational certifications and other claims).

Not to mention that a big part of investing in start ups is just ape jpegs with extra steps (i.e. "greater fool" theory).