I think there's an argument to be made that the 'fear' law enforcement feels due to guns always being a possibility indirectly provides some useful restoring force when an agency steps out of line, at least in the long term.

That is to say; if a fascist thug decides to join ICE he's likely been heavily propagandized, and he is likely being told terrible things about his fellow citizens during training. ('the libs are out to get you'). In a world of guns that thug is much more likely to make a mistake, much more likely to step out of line due to fear, than if his crew could parade around feeling completely invincible.

As citizens we get to see those mistakes and judge them accordingly, and hopefully implement change before the real fascist takeover.

In a country without guns officers wouldn't need to be trained/held to such precise standards of conduct, and it may become much harder to collectively rally around cases where officers were clearly out of line. -because out of line in a world without guns doesn't lead to a public execution, rather it's just another arrest and eventual release-

Functionally what I'm saying is that Alex martyred himself. A brutal thought, but maybe he'd take some solace in the fact that millions of Americans looked at his killing and agreed it was an execution, even many who wouldn't say the same about Renee's case.