I agree, the tight deadlines make them copy paste and progressively increase the assets size without any eventual cut down on unused code or assets.

Whenever there is a thing like this, you can always pointing back to a couple obvious curlprits cause it's almost always that case.

• There is that decision making group think it is fine and just push through instead of listening to their own people.(look at unity runtime fee a while ago.)
• There is simply enough time to trim it cause the trimming part keep getting pushed back because priority.(by the same group above)
• You'd be surprised that efficiency didn't really scale up with amount of people involved in a project, nor how experienced the people has been in the industry. Because the tech is a moving target every year.
• The brain bleeding from inadequate pay or inadequate management is astonishing even for fairly well managed company. Your can have people doing literal jack shit and only pay lip service that like to put their finger into stuff to justify their cost, and when people actually couldn't give another fuck and decides to leave now you have some muddy place/project to work with.
• C-suites looking for getting acquired/spring board higher rather than making actual good stuff. Their performance evaluation aren't tie to the quality of product.

Gaming industry are not that special where the whole group of people can just go to work and scroll all day.