It will be very difficult when total tax rate reaches 100%. It is already over 60-70% in some places, so people's lives are managed more by the government than by themselves, but when you reach 100% and the disposable income gets to be 0 it is hard to extract more tax.

Also: if you are willing to pay more taxes don't even consider forcing others to do the same, that is rude.

Yes, in many jurisdictions voluntary contributions are accepted. I assume you've already explored this option?

I am not interested as I don’t think voluntary contributions can change anything. This argument goes both ways: why not lowering taxes since people can just donate instead? The next thing you know you don’t have hospitals, roads, police, firemen, army, education, healthcare, oops

The relevant phrase is “put your money where your mouth is”.

Yes, which is in funding organizations and movements that aim at educating people (like you) about the benefits of social programs and taxes.