No "drive by chatters" showing up at my desk with "Hey do you have a moment?" or just shooting the breeze but dumping me out of the zone.
I'm not tempted to buy lunch every day, wasting money and time.
I am more productive; there's nobody playing pingpong, shouting across the open office to each other, cheering at winning in a video game, or delaying me in the hallway on my way to a conference room.
I don't have to book conference rooms and pressure the previous meeting to vacate on time.
In a global company, we don't have situations where the one or two remote people are an after-thought to meetings that are being held in person for everyone else. In a meeting, everyone is on the same playing field. There's no office with five people in it, and then one person on a screen.
Tools have become good enough: Jamboard, Figma, and other collaborative document tools, Meets / Zoom / Teams, tmate / tmux (for terminal-based collaboration; vim, etc.)
Pair-ups and tutoring can be ad hoc, and when they happen, I'm not needing to book a room or annoy my open office neighbors with chatter.
My company has people working in every US timezone, plus several timezones in Europe and Asia. If I need to take a 6:30 AM meeting to accommodate folks in India, that used to put me in a position of not having a good option for when to finally commute into the office; go in before? That's rough. Go in after? That might disrupt my day. Now it doesn't matter.
It's easier to just take a walk, or to pick up a kid from an emergency at school. This de-stresses life a little, making me able to focus better while I'm working.
There are cons, of course:
In-person, face to face communications includes body language, facial expression, and a bit more freedom to relax and discuss. This hurts more junior developers who need more day to day, hour to hour support.
It's harder to build team loyalty. You have to plan to spend time together in virtual meetings and possibly occasional in-person meetings.
Whiteboarding is a little rough still. Figma and Jamboard help, but it's a little harder to brainstorm as a group, and it doesn't just happen as naturally as an in person conversation could migrate to a whiteboard.
Not everyone has a good place at home to work. I'm lucky that I have a couple of options at home; a nice office that is in a more common area in the home, and then a more "bat cave" office that is quieter and secluded for when the kids are home and noisy.
Let's be honest; it can be fun going to lunch with your coworkers, exploring the neighborhoods around offices, and so on. We miss that sometimes.
Some people have trouble unplugging at the end of the day.