I am sure you could reduce complexity quite quickly but then you are building a different product. The selling point of an eCommerce framework is the structure and existing feature toolkit. Like modules, events, mechanisms to safely override core functionality and all of that. I am also sure you could build a more compact eComm framework, but I think you would start to trade off structure for reduced complexity. For me though, more structure equals less need to worry about the complexity as that's been abstracted away.

I wouldn't mind seeing the other side of the fence though, I will admit I have worked in enterprise codebases for most of my career so I am definitely biased.