My experience is that, when it started (for me, 2004 was my first work-issued laptop), it was more about what the GP was saying. The first time I had a laptop for work, I was expected to be in the office from 9 to 5 (or longer), and was expected to be available to respond to occasional emails in my off hours, sometimes taking calls, facilitated by having that laptop that I could bring home. I was fairly junior; others more senior than I was would be taking calls (for which they'd need their laptop) from home and doing substantial work nearly nightly. (We did a lot of work with hardware and software firms in east & southeast Asia, so we'd have calls at US-weird hours.)

But even in the few years before the pandemic, I was where you're talking about, working from home a lot more often, and replacing office-work hours with home-work hours, not just adding extra hours at home to my office-work hours.

I think this still depends a lot on the company, though. I know people who are expected to be in the office for 8+ hours a day, 5 days a week, but still bring their laptop home with them and do work in their off hours, because that's just what's expected of them. But fortunately I also know a lot of people with flexible hours, flexible home/office work, and aren't forced to work much more than 40 hrs/wk.

A laptop as the primary/only machine had been normalized at tech companies a long time before covid made working from home very common.