According to Wikipedia, the first European war to break the Thirty Years' War's record of eight million casualties was WWI. How come the Thirty Years' War was so much bloodier than other wars of its era?
u/Eoinp gave an excellent answer to this question a couple months ago. I'll link the thread below.
I concede the point about the War of the Spanish Succession (it's personally my favourite war) but you have to understand that in terms of scale they might have been comparable but the Thirty Years War was particularly worse simply because of the number of nations involved.
The Napoleonic Wars perhaps matched those but it was more a disjointed series of conflicts that were fought in primarily different theatres as opposed to the Thirty Years War which had a central conflict zone.