I'd also observe that the initial companies that took on the purely digital side of things (e.g., Second Life), might have just been too early in a world not ye

I'd also observe that the initial companies that took on the purely digital side of things (e.g., Second Life), might have just been too early in a world not yet as digital as it is today. That is, people didn't have enough of a digital life that a service aimed exclusively at it would be of sufficient value. That could change as more of life becomes fully digital. So it's possible that the online/physical thesis is "fighting the last war," so to speak and future companies might not want to pursue that.