The quality of the assets for these moonshot unicorns declined over time (IMHO partially because they were increasingly moving away from pure-bits to bits-and-atoms, making business cases much harder to execute and expensive to fund) and then the macro backdrop soured and here we are
Bonus: here's what StableDiffusion drew for "A dream of moonshot unicorns, 4k trending artstation" because why not... https://i.stack.imgur.com/sFxIw.png