"Vast majority" might be an overstatement, but if you work an 8-hour day, commute for an hour each way, and take an hour for lunch (which, let's face it, is often with co-workers and involves work talk), that's 11 hours doing things that you probably wouldn't be doing if you didn't have to work. If we assume 8 hours of sleep, that's only 5 waking, non-work-related hours.
It's... pretty lame, honestly. All these modern conveniences and we're working more than ever these days (in the US, at least).
Also not really sure where all these "comfy tech jobs" are; every tech job I've worked in the past 15+ years often has people working ~10 hour days. I'm not aware of many people in tech who work 9-5 and that's it.