If you're fully remote then you need to behave that way even when you're in an office environment. Sure, have in-person meetings when you can, but make sure remote folks are 100% present and enabled, otherwise those that choose to work from home will be less present - even in a healthy WFH culture.
As for loneliness - a couple things help with that. First, get together in person for a week or so every quarter to link up. Second, you don't have to work from an office when you work remote. Third, working in the office starting out to understand the culture then going remote is helpful for networking / understanding the rhythm of those in the office if you do work with full-time office folks. Being within reach can be helpful but not required. I'm close enough to the office that I can go in for big meetings or in-person things without too much heads-up, but I'm not expected to be there, and I'm probably there once a month, max.
As for addiction - clearly you gotta prioritize to make sure that stuff doesn't destroy your life. If remote work doesn't work for you, definitely don't do it. Doesn't mean it's not magic for many of us.
Full time working from home wasn't great for me -- it felt isolating and I found myself running a lot more just to see other human beings. (Of course, running was good, but the motivation for it was kind of weird.) I'm shy and naturally form relationships with people I bump into regularly, but I still have no clue to how to do it intentionally, and I also feel uncomfortable practically living at coffee shops.
I got into a bullshit mobile game, I didn't think it was a big deal to just leave it open all day while I worked.
Checking in between every email, and every commit, to make sure I was perfectly optimizing my in game economy. Eventually I became one of the top players in the world and was spending 4.5 hours a day just to keep my spot in the top 100.
If I placed in a world tournament in Smash Bros that was streamed, then I went on to bomb the next 5 tournaments, I'd probably still be trying to get that glory again
As I'm not a morning person this has been great for my mental health, and it's a good combo of "WFH" with "real work" without the addiction issues associated with the former.
Sometimes it's just "hey...you seem to pretty consistently miss the early meeting...you good?" or "you know you haven't been hitting it like you used to...but you seem to be killing it in EVE Online". But I've been through an employee where it was performance falling off->odd behavior on calls->slurring incoherently on calls->intervention->short term disability. Fortunately, recovery can work and they're back. In the office.