The whole point of running and using browser apps is that they are guaranteed to be sandboxed - Node.js breaks this sandboxing 100% which makes it more powerful

The whole point of running and using browser apps is that they are guaranteed to be sandboxed - Node.js breaks this sandboxing 100% which makes it more powerful but also inherently a mess security wise. This mess can to a certain extend be accommodated on the server side but certainly not on the client side where code from 1000s of devs will eventually be run without vetting.