Well, they're probably ongoing challenges that any company needs to consider--and I'd argue that culture and communications can be challenges even within a company location as it scales. I'd shy away from ever saying they're "solved."

But the fact that there are successful companies with a significant percentage of remote and/or distributed workers suggests that they can be solved well enough.

There are plenty of very successful 100% remote companies, including GitLab, Zapier, Automattic (Wordpress) etc. I think it's fair to say they've solved it well enough.

Traditional office space also comes with its own fair share of challenges and problems.