The PS2 is one of those consoles that had fairly bizarre hardware architecture compared to say, a PC for example.

Developers took a few years to figure out the hardware and really learn how to take advantage of it. They didn’t get much or any pre-release dev time, so they were learning how to use it while gamers were just getting their hands on it. Thus, the better titles came later in the consoles life.

https://youtu.be/_PiiXM51oBo