Cubes are used more because they are cheaper than building thousands of offices more than they are used because they are flexibly reconfigured.
Individual offices are great for privacy and noise control - especially if one makes a lot of calls.
Shared offices in my experience are fine - you sound like you have some social issues, no offense.
The only things I would worry about sharing an office with another are hygiene and if the other person is a "lights-on" worker when I am a "lights-off" worker.
I shared an office with this developer in 1999 named Srini. We were both lights-off workers. I was IT, he was development - so it worked well.
The only issue was that he was rather comical to look at - so whenever we would have lengthy conversations, I would giggle as he was talking, which annoyed him because he would be talking about something serious and I would be laughing. He would ask me what I was laughing at and I would always have to say "nothing, your comments just reminded me of something else that I thought was funny."
I had to avoid looking at him as he talked for this reason.