I've never been lucky enough to have friends I can regularly go on trips with. So pretty much always solo, out of necessity.
In fairness, I prefer my own itinerary, and pace, so perhaps wouldn't change that now.
I also avoid UK twitching, with a view to seeing many species in their home range, so some trips with me would be frustrating for others, as I'd be spending time hunting for species often encountered as rarities in the UK.
My Daughter has a very refined taste in Safari holidays, so every so often, if I manage to save up enough money, we go together. Just to try and add a disclaimer that I'm not a hermit!
I don't think I could handle a group trip, 5 or more people, of any duration beyond a couple of hours. Except perhaps a boat trip, or safari jeep where the pace is dictated to you, and we all have the same view.