A lot of it is sandboxing and the multiprocess architecture that requires. There's lots of IPC. Custom Chrome builds can disable the IPC and run everything in o

A lot of it is sandboxing and the multiprocess architecture that requires. There's lots of IPC. Custom Chrome builds can disable the IPC and run everything in one process, but Electron doesn't because they try to minimize the number of patches they apply so it's easier to keep up with Chrome code churn.