I sorta want to agree with you but I don't think you did adequate due diligence on understanding the phenomenon.

As of three years ago, roughly 17% of mass shooter events ended with the targets overpowering the shooter. It's true that only 1/5 of those were accomplished with a firearm, but this suggests a significant flaw in both your logic and your statistics: https://www.kxan.com/texas-mass-violence/do-good-guys-with-guns-stop-mass-shootings-heres-what-the-statistics-say/

Also, you didn't mention what fraction of attempted violent crimes were prevented because the intended victim had a firearm. This is extremely relevant, because humans do not commit crimes at random. This would need to be looked at in two parts: (1) what are the rates of crimes initiated against people openly carrying vs. those who are not; and (2) what was the success rate of crimes initiated against people who were concealed carrying vs. those who were unarmed? (Home invasions should probably be their own category.) Guns are a credible threat. You wouldn't expect them to have to be used most of the time in order to alter the outcome.

Guns might still not come out ahead, but you're not asking enough of the right questions.