When I worked remotely 2 days per week this was a problem for me, because all the people I worked with were together in an office. I felt quite isolated on those days and enjoyed going into the office to see people on the other 3 days.
However, when I changed jobs and was almost completely remote it was a lot better. Firstly I was working with other remote people so we communicated in different ways and not just about work. Secondly I made more effort to contact other remote workers nearby and meet up with them for coffee or lunch.
On balance I much prefer remote working to office working.