Turning a machine off loses any existing application state, and requires both applications and the OS to be re-launched.
When I put a machine into standby, I want it to go in a standby state, and then stay there until I explicitly wake it -- not keep doing whatever background tasks the OS developers, app developers, or whatever other third parties think they need to keep doing.
Btw, what’s the functionality which needs this half sleep state with running WiFi and Bluetooth? Laptops worked for decades without this, and I’ve never felt the need to change this. It caused headache for me too many times, and I don’t even know why I would need this.