Like maybe I go afk 30-45 mins here or there when I normally wouldn't in office. But for me, I put in more hours overall. A key to this was learning to not have my personal laptop open to the side, and avoiding distractions like social media and idle browsing.
YMMV of course, I think it can really depend on the person and their life situation. But the same could be said of anyone remote or not when it comes to productivity. It's on the managers to measure if things are getting done or not, which is the most important thing.
Common counter argument to this is that the manager sucks because he/she can't measure the work otherwise. But from managers perspective it is much easier to force people to be on-site than fix his/her own problems.
They also mentioned avoiding other distractions: That's the main feature of remote for me, after many years of wearing headphones all day in various offices.
Because if they're not, they miss deadlines.