And being in an office doesn’t help if no one on your team is in the same office. If you work in a large company that has multiple offices, you are still going to have the sane problem because eventually the person you need is not going to be in your office.

Even the small companies I’ve worked at (100-700 people) had multiple offices where you had to coordinate time to meet with the people you needed.

I’ve also worked remotely for the second largest employer in the US. Amazon has internal “interest” channels for each service team (the team responsible for an AWS service). Anyone could ask a question and usually one of the developers of the service would help.