I don't have a lot of knowledge on ECS, are there any good articles out there that compare it to OOP?
[0] https://www.dataorienteddesign.com/dodbook/
[1] For instance, objects in OOP are typically bundled with other data related to the object. As an example, in OOP a Door object could have float X,Y,Z coordinates, an enum for type of door it is, a bool for opened or close etc. This leads to inefficiencies in cpu cache usage when you are iterating through a list of doors and not using every field of the door object.
See this GDC talk for why this matters in the gaming world: https://www.gdcvault.com/play/1022248/SIMD-at-Insomniac-Game...