You can’t use what you believe to be “true capitalism” in practice to prove that the practice is true capitalism.

No, but it might help to explain that there is no such thing as "true capitalism" because capitalists have never needed "true capitalism" - that is, unless you want to argue with the people who obsessively calculate Jeff Bezos's net worth.

but you may have noticed that none of the examples I gave serve that purpose.

Are you not aware that your taxes fund the police? You know... the violent institution that was specifically invented by the capitalist class to protect the property of capitalists from the very people capitalists parasitize off?

There is no point in trying to sound smart when it's blatantly obvious that you can't see what's going on right in front of your nose, Clyde.

You are confusing capitalists with those who have benefitted from capitalism.

No... I don't think I am.

People in power seldom support a system that allows them to easily lose power should a better alternative arise

So this "efficient-market hypothesis" isn't worth the paper it's written on?

No surprises there.

To claim that socialized aspects of a generally capitalist society are not actually socialist

The term socialism has a very hard and uncompromising meaning which it has retained no matter the efforts spent trying to warp it. Unlike concepts such as fascism and capitalism, socialism actually requires logical consistency in order to be useful to the people it has always been intended to be useful for.

Extraordinary claims require extraordinary evidence... and if you claim that anything has been "socialized" in a capitalist society (apart from all the real costs that the working-class has to bear in such a society) you need to provide evidence for that.