What's solo diving?
I'm not a big fan of showing up at dive site by oneself and doing a dive all alone. Redundancy is a must, but even so, it's riskier.
OTOH, read about every fatality. Some were diving alone, but most had buddies and were also in a group. Somehow the buddies became separated one died for some reason. Close buddy diving is highly overrated for safety. It only takes a split second for separation or for a real problem to arise. Ask any instructor who leads OW students in poor visibility.
The other reality is that if you are carrying a camera, you might as well assume you are alone, because at some point you will be. The best case scenario is that you can find your buddy in an OOA emergency.
A few years ago, I was on a wall in Palau. My mask started flooding. I had a slap strap with those plastic clips and one had come undone. So while holding my rig, I take the mask off to redo the clip. I take a breath and it's salt water. I do it again, same thing. I hit the purge button, but my finger goes right through my mouth piece. When taking my mask off (while grasping the camera), I inadvertently yanked the 2nd stage off of the mouth piece. My primary 2nd stage was dangling somewhere and I had no mask on while holding a double strobed camera rig. That and I hadn't had a breath in about 30 seconds. I hate when that happens.
I was also on the tail end of the group. No one saw any of it. I was on my own. I just got myself back together and rejoined the group.