If you worry file size, you are probably at the wrong place because the most huge installers i got are both from CDPR:
Witcher 3 with all the Extras: 145 GB
Cyberpunk 2077: 113 GB
Installed files are much smaller because this is a "general installer" which can handle any languages and options. Yet, clearly... those are no small games.
There are some shops only focusing on Indie games i guess... you may be knocking at their doors. GoG, influenced by CDPR, are rather a "hybrid-shop" nowadays and focusing on old and new games together. Although, the margin of old games are bigger than what we can see on Steam.
However, GoG never was focusing on small games... old is small but not always and not forever.
Of course "old" is a very relative term: To some people a game over 2 years of age is already old and to other people a game above 20 years is old... any other game almost new... so we fail to have a usable term.
I know someone telling me: Her notebook is "almost new", yet the age is actually over 5 years already. And she wonder why her keyboard is not working properly anymore. My answer would be: This notebook is already old and it has never been designed with high quality in mind, so... having a glitchy keyboard at this age is pretty usual. So yeah, everyone got some other views and always very relative terms.
Zimerius: The FFXV 4k resolution pack is 66.2 GB installed
Well, you clearly got no interest using this pack if you do not own a 4k screen. Those owning a 4k screen are usually at the same time owning lot of space and a good GPU too. Without a 4k screen you do not need those textures, makes not much sense as you are almost at the limit the screen can handle.
It would make no sense owning a powerful car but unable to pay the gasoline... more "powerful" tech comes at higher cost.
Nowadays the majority of the gamers are still playing in 1080P (around 3/4), yet the amount of 4k gamers are slowly increasing because 4k is for many years a new TV standard.
Yet, there is still over 100 million PS4 owners and "only" around 40 million PS5 owners, reason why most devs still was supporting a PS4, although it is now already 10 years of age (in hardware-terms, very old). We clearly can say, the mainstream-customer is not very "tech-affy", they try to use the old tech for as long as it may last... in usual, due to different reasons, but mostly economical. Every cent may count, however... it does not help that the cost of living are increasing world wide, at some locations even with crazy speeds... although, it will become "a matter of priority".