On the other side of this, I feel like I'm seeing I'm seeing "leverage time zone differences to accelerate the development process" in hardware engineering job postings with increasing frequency. I can definitely see where there's an efficiency gain for heavily sequential tasks like PCB design bring-up to have teams working in shifts without anybody losing brain power by working outside of normal hours.
"When things need to get done quickly or a problem can only be resolved by talking directly"... and that problem occurs at night in my timezone, a team mate who's awake can deal with it with a rested head and no burnout in her or his day.
Admittedly, there are many companies who don't need 24x7 business continuity and are perfectly content with 10x5. For them, this is unnecessary complexity.
As long as we can find good enough people in our state, it’s just not worth the hassle to add more HR challenges than we have to.
In my company it's also very difficult to hire a full time employee in another country due to all kinds of regulations and the overhead they entail.
My prediction is that in the long run a lot of companies will still prefer people who are close. Managing remote people effectively is very difficult. A lot of managers will fail doing so. And a lot of people are also not cut out for remote work and need interaction at the office.
I remember when offshoring became popular in the 90s it looked all work would go to India but this didn't happen either.