The first aspect is obviously rushed development. Developers and artists can absolutely take some time to make games run smoothly with smaller assets. On the contrary, to complete a game as fast as possible you can employ many time-saving tricks that waste ungodly amounts of resources like duplicating a ton of stuff ect

Secondly, compressing files to make them smaller on the disk increases loading times, and on a capitalist standpoint it’s a way better choice to not compress anything because preying on impulsive playing is more important than making your game easier to try since the dominant economic model is to milk your existing playerbase rather than trying to expand it