The risk in these new keywords is very low as most of the domains you find at hand register cost.
I wasn't speaking of "meta" in particular in the moment, rather of it 6 to 9 months ago when it was a risk.
Trend domains tend to be the highest risk investments with very few actually paying off. Meta was just a bigger hit because more investors won with acquisitions by Facebook for potentially future projects as it's cheaper to pay $10,000 for MetaABC now than after it stands up as its own company. Further, they created something new that businesses wanted to be apart of.
Think of the Drone trend—DronePhotography.com is good but
DronePizza.com is not because the only establishments that could deliver on that while scaling would be something like Pizza Hut. Also, they don't need the domain, just the user input on delivery method as they have already acquired the customers, just didn't ship the infrastructure (if they were able to do it) out to franchises.
If Facebook's rebrand wasn't meta, there'd be about 90% junk domains (some would still make sense as a brandable).