Right now with the current 18TB hard disks the gaming box can reach 40TB maximum. Beyond that a storage appliance is needed. At present the game collection is far below 40TB so there is no worry at present. The game collection does grow over time and the size of games have also grown. So far a single 12TB disk has been able to handle the library.
The expected 20TB disks did not surface in large numbers. A lot of large scale data centers need bigger disks to handle the influx of data.
Looking at servers there are some new 1U designs with 12 disks laid flat. Such machines are low cost and can be useful in a studio. The big 60 disk servers are stuffed into 4U servers which does have a slight advantage over the 1U server for big storage.
The thin 1U server still can hold 96TB using the current 18TB hard disks. The larger 4U server is 1080TB which is just entering the PB range now. 8 servers in a rack is 8640TB. NASA uses these servers like they were going out of style.
20TB disks should surface some time in 2021 so that the data centers of the world can rip out all the old disks and upgrade. Sadly the resale value of old hard disks is pathetic. Backblaze has more servers with smaller cap disks so they need a lot more floor space.