@lololulu19 ... answer can be found from [Google NFO] ...
Blu-ray Disc (official abbreviation BD) is an optical disc storage medium designed to supersede the DVD format.
The plastic disc is 120 mm in diameter and 1.2 mm thick, the same size as DVDs and CDs.
Blu-ray Discs contain 25 GB per layer, with dual layer discs (50 GB) being the norm for feature-length video discs.
Triple layer discs (100 GB) and quadruple layers (128 GB) are available for BD-XL re-writer drives.
25 GB per layer [single layer]
50 GB dual layer
100 GB triple layer
128 GB quadruple layers
How much space does a quadruple-layer Blu-Ray have?
128GB
The BDXL
format allows for additional recording layers beyond the current dual-layer format (with up to 50GB in storage capacity)
to provide triple-layer discs (100GB) and quadruple-layer discs (128GB).
Additional NFO : https://www.quora.com/Does-a-BluRay-disc-have-25-GB-or-33-GB-per-layer /
https://forum.videohelp.com/threads/391948-What-s-up-with-Blu-ray-layer-capacities
They are too big to be put on DVDs
There is no reason for those games to be that big.
Video Graphics and HD/resolutions are involve ...
[modify a game folder] you can see data's in size ... is all about programming ...
They are written as multi-volume archives in a BLUE-RAY Discs ...
Now if you ask DVD format, SIZE should be divided from 8.5 dual layer discs / https://en.wikipedia.org/wiki/DVD-R_DL ...
so you need 13 DVD discs to hold 100 GB 
So why make it difficult, while there is a digital offer as an OPTION ...
@lololulu19 It's 2024 soon those DVD eras are being phase out 
