Unkalibriert: Its to much in my opinion, but that's probably just me. I don't like game installations being larger than 10GB. >.<
But the site says ~24 GB, so you're fine.
It's not enough in my opinion, I'd like it to be 200GB, but that's probably just me. I like my game installations to be as massive as possible to maximize the gaming experience to the fullest and give me the best quality graphics/textures/audio/video bang for the buck. If I want to save internet bandwidth I'll download Zork I+II+III rather than buy a new AAA game. :)
In general computers and technology increase over time according to Moore's law which is essentially that they double in capability every 18 months pretty much like clockwork. Computer upgrade cycles happen roughly in line with this as well naturally and developers writing software end up targeting what people are using in general and since the hardware follows Moore's law certain software in particular that which can push the envelope on the hardware tends to follow Moore's law in terms of the resources it uses too because the resources available are tracking Moore's law.
So if the average game uses 20GB one year, 18 months later the average game will use 40GB, another 18 months -> 80GB then 160GB etc. It's almost like a swiss watch.
And while some people upgrade regularly or at least have a more current system, there will always be people that don't have a current system or Internet bandwidth etc. too, so there will always be people thrilled to get the next big massive game that pushes their PC to the limits and people who either can't run it or their Internet sucks. The numbers will scale over time but it'll always be like that essentially. Blame it on Moore, he started all of this. :)
I welcome our terabyte sized video game overlords. When The Witcher 4 comes out I'll upgrade from 25Mbps Internet to 100 or 1000Mbps Internet to download it if need be because WITCHER 4!