It kind of baffles me that this needs to be a bill. I guess I'm lucky that I've never worked for a company that required me to be constantly online. (I work remotely for a US company, work European working hours, and nobody requires me to be online outside of them.)
You are lucky. This bill is for the unlucky, because luck is not a strategy as it relates to labor rights and protections.
I've worked at companies that don't outright require it, but they utilize a few workaholic employees to set an expectation sane people can't live up to. It creates a stressful environment where expectations are unclear. Combine that with the current job market and you effectively hold your employees hostage.