(And I feel bad saying this since Meta obviously did waste eleventy billion on their ridiculous Second Life recreation project ...)
So please don't mock the spend. Big spends fail sometimes, and at least people were paid to do the work.
On the other hand, Meta's experiment is primarily CEO-driven. The outcome is predetermined, changing direction is not possible. Sure, clever engineers get to draw the rest of the owl, but that's not very useful when it turns out that everyone needs a horse instead.
They are spending a fortune, but rather than getting 900 crappy ideas to throw away and 100 great ones to pick from for continued development, they are developing 1 technological marvel nobody is interested in.
Just because you spend a lot of your money on R&D, doesn't mean that each R&D project is automatically a good one. You still have to make choices between them.
If they'd spent the money researching nuclear fusion or space flight or a new way to develop microprocessors, I would be cheering their efforts even if they had failed in the end.