All of my big tours are solo, as are most of my day rides as well, solo has really been my default status for many years.
I do have some work colleagues though who are also into gravel riding and bikepacking. Last year three of us went out into the Hartz mountains for an overnighter, I was a little anxious about how it would go but it turned into a really chilled and memorable trip. This August two of us went last minute up to Hamburg and rode over the heathland back home, we bivied out under the stars and again it was a really relaxed fun trip. So I'm really not adverse to riding with others if I know them well and we have the same shared objectives.