I’ll attempt a steelman and say, no, employees are not doing deep work from 9–5, but I could see being in an office 9–5 setting the stage for a lot of deep work to be done. Moonlighting for another company I could especially see as detrimental to focus at work.
Deep work with an open office? Dont make me laugh. Please for the love of god bring back cubicles.
The steel man is that in the office you get cross team pollination organically. Team lunches, talking about an idea with another team on how to do something better as in that moment the idea came up. This happens more often in person than remote.
Does it need 5 days a week in the office? Absolutely not. 1-2 is plenty.
> Deep work with an open office? Dont make me laugh. Please for the love of god bring back cubicles.
Or doors.
25 years ago, Microsoft Redmond had a slogan: "Every dev a door".
In early 2000s, it began to be two devs per room. We all know what happened since. Open offices save facilities concrete money per seat. Productivity lost from lack of deep work is not a line item anyone knows how to track.
The "every dev a door" plus "pair programming" was shown by studies from groups like Pivotal Labs as being optimal for working code, but ... and a big but ...
Companies intentionally optimize for things other than working code. You get what you measure and they measure what's easy instead of measure what matters.
// See https://lethain.com/measuring-engineering-organizations/ but also https://lethain.com/good-eng-mgmt-is-a-fad/
The nature of modern offices pretty much prevents deep work.
You're not going to get deep work when you pack people like sardines into neat rows of desks, where pretty much at any time someone within one row away is going to be in a meeting - conducted of course over teleconferencing software. Or some people will talk (honestly, being in the office mostly translated to chit-chat for me).