The man with the gun to his head doesn't have much of a choice if he wants to live. You, though, have a choice between criticising and defending the man with the gun, and you're choosing to defend him.
They have since announced that it will be capped at 0.1% of a bank's assets: https://edition.cnn.com/2023/08/09/business/italy-bank-windfall-tax-change/index.html
Not to be That Guy, but Discord is another corporate proprietary walled garden just like Twitter and Reddit and given recent experiences I think it should be avoided by the Fediverse community. See also this blog post (I am not affiliated with its author, I just think it expresses the point well).
There are several alternatives. If you want real-time chat, Matrix or IRC would work. If you just want to make announcements, an RSS feed or mailing list would do the trick.
Just my two cents. Thanks for your work in setting up and maintaining this instance!
Edit: Bonus see also
I use a lot of free and open source software, and some of the stuff I use a lot I support with donations. Python, Mozilla, FairEmail are examples of software I have donated to. Wikipedia also.