I have ridden with groups and ridden alone.
I much prefer solo for my serious riding. Set my own speed, explore where and when I want, think my own thoughts, stop when I want - take a picture or whatever. I am almost 64 yo, and just don't wnat to put up with the extra social effort and whatever goes with group riding.
However, I do also ride with my wife, but this is at a much slower pace and not really my serious riding.
A far as safety goes, some of the very most "unsafe acts" are groups of riders riding triple abreast or more, zooming through stop signs and occasionally stop lights. IMHO, you are MUCH safer by yourself. As far as technical backup, keep your bike in good shape, carry a multitool, spare tube, pump, patch kit, etc., and a cell phone.