I started diving solo some years ago because I just couldn't find enough people that wanted to or had the availability to dive as much as me. Once I started diving solo, I realized how much I enjoyed the freedom of it. Do what I want, as long as I want (or short as I want), responsible only for myself, my own safety, and my own experience. By nature or by experience level, when with others, I tend to take on the responsibility or duty of care. Even if it is only in my own mind and not something we have discussed and agreed upon. So much so, that I feel responsible for their "experience". Probably a reason I feel more relaxed when diving alone.
That being said, for the shared experience and camaraderie, I do value being with others and friends driving to and from dive sites, during surface intervals, at the bar or restaurant after diving or at breakfast before diving or on dive trips/vacations.
But, by and large, I am perfectly happy to be by myself under the water. Looking at my dive log and doing some math, 28.5% of all dives I have done, have been intentionally solo. 71.5% were buddied up with others.