Yes pepper spray is much stronger than bear spray is.
The bear spray is less powerful than pepper spray so that makes the bear spray not very effective in warding off humans.
So if you had a human attacking you then you'd want to use pepper spray but if all you had was bear spray then it would be better than nothing at all.
But bear spray and pepper spray are different .
The bear spray has a much lower concentration of oleoresin capsicum, and should only be used as a bear deterrant and if you have pepper spray then use it for human attackers or dog attacks.