For the humble consideration of the group: pepper spray is really effective at what it does and taking away someone's vision is one of the greatest advantages you can take in a fight. I also agree that guns aren't the exodia for a fight that one might believe. I put stock into knives as a deterrent, but not as much as declaring you have pepper spray and brandishing it.
With that being said, in terms of being a deterrent, I also think a flashlight/tazer combo is a potent deterrent, perhaps superior to pepper spray. In that pepper spray let's someone fuck around and find out because it can look unassuming, if you get a light shined in your eyes and then hear the loud sound of a tazer, I have to believe that you lose the will to fight far faster. The light takes away their vision while giving you more which is super overpowered.
A YouTuber who was an ex cop, martial arts instructor with experience and training in use-of-force has spoken multiple times that "just run" isn't the golden ticket that I once thought it was and I find it persuasive. Even if there is no win condition in fighting besides getting home safely, protecting others, injuries, if they're faster than you, etc. would be part of the calculus too. Which really sucks and is depressing. Not everyone can have a decade of competitive combat sport experience. Things like walking in a group, having awareness of your surroundings, looking tough also make you look like you're not the easiest target in the room which is probably what a random aggressor is looking for.