What!?!? I don't necessarily agree with OP, but this is the exact opposite of my experience (mostly observing others). One of the main downsides of WFH is the "always on" nature of it.
I usually left my laptop at work, and ignored my phone before (after all I'm not at work). Now you're always set up to work, so there's no reason you can't respond at 8PM. I don't, but many of my colleagues do.
Most of my coworkers, especially the ones that would be leaving early for work life balance reasons, work all hours, and I get randomly pinged at 5:30-8 by people that would just be done for the day. They don't need to commute, so they have less pressure about working at odd times, and want to show managers the advantages of the WFH thing, so it won't go away.