It doesnât actually need 130gb of updates, thatâs the fun part. They probably only made a couple gigabytes of changes at most, just their shitty folder/packing structure requires downloading every single âunitâ of the game again because they made minor changes
On the hand hosting and bandwidth cost have come down significantly to the point where the price per gigabyte is in the 0.0 cent region.
On the other hand, developers are incredibly expensive, especially when they could do something that results in even more value for the company.
At the end of the day, downloading the full file is a reliable and all in all cheap way of providing an update, even if it's annoying and frustrating as hell to download 138GB just because one bit was flipped.
It is extra work for them so they make more money by not having a team implementing a patching system that can handle distributing only the changes. They just don't care.