What is the contribution of the bus to overall power consumption vs the CPU and DRAM chips themselves, let alone the screen? I find it hard to believe that that

What is the contribution of the bus to overall power consumption vs the CPU and DRAM chips themselves, let alone the screen? I find it hard to believe that that is really an important design consideration leading to soldered-in RAM. I had a Lenovo Stinkpad Carbon X1. The soldered-in RAM started to fail, causing memory corruption. That machine is now a brick, and I am still pissed off about it. Modular RAM is fixable RAM.