I think the problem with the comparisons between the two Dark Lords comes from a serie of thoughts:
2. Voldemort, in the vast majority of his appearances in the heptalogy, seemed more than a little bit crazy. Same with his followers. He had more or less sound plans and we know he and the Death Eater in charge are at least intelligent and dangerous enough to pull a coup d’état without notice. But we don’t get to feel it, because we only get to see how he attained power in the ministry perifellicaly. Harry’s limited POV is only centered in the personal danger to him and his friends not in all the ideology and machinations and magic that a Dark Lord and his followers employ (except for the Horcruxes and the Unforgivables). So we are left feeling a bit disenchanted with him, because when the big bad wannabe dictator seems so dangerous and crazy even to his own followers (the sanes ones at least) you don’t understand how he even got to be in that position of power. Not like we are with Grindelwald know, who seems much more sane, intelligent and manipulative that Voldemort ever appeared upon his resurrection or even in the last flashbacks of his youth in book 6. We get to understand why, even when we watch him being a ruthless murderer, people want to follow him.
3. Voldemort even in all his glory, was not a ultra-personal failure to Dumbledore. He was a Hogwarts alumni that yes, gave Albus a lot of headaches, and he killed another classmates, etc etc. But while Dumbledore was able to play mind games with Riddle and affect him, it wasn’t mutual, not like with Grindelwald. There is a lot of lost feelings between them (we suspect), so we are more invested and it also has the side effect of making Gellert seem more dangerous an enemy to Albus. Although that isn’t necessary true.
4. It is understated in the books and supplements, and now from the films that Grindelwald hold of Europe equals (more or less) the Nazi ascension. So, at least since the 30′s to the duel in 1945, in a variable european territory because of the conflicts. Voldemort maintained fully control of magical UK not even a full year in the end. Of course, he was a menace at least since the start of Harry’s parents tenure in Hogwarts to their ends in October of 1981, and again since the end of fourth year to the seventh of Harry’s. Is question of thinking a little, but again, even the horror of a civil war and dictatorship doesn’t measure in our modern occidental minds against a war that was explicitly stated as the magical equivalent of WWII for much that it didn’t affect magic UK or Ireland.
5.The focus of the films. We are seeing so much more of Grindelwald that we ever did of Voldemort in all HP films combined. Same that will happen with Dumbledore, I think, in the future films of FB&WTFT.
Of course all of the problems above have the same root: the different focus of the HP story and the FB one. In the first, is Harry journey against the stereotypical EVIL with touches of realism, while in the FB is the much more realistic uprising of a magical fascist. Not that Voldemort wasn’t one mind you, and the start of book 7 was delightful in that regard, but it never was quite the focus of the story as it seems it is in the new movies, incredible new magic and all.
And that is all, roughly. If somebody want to point something I missed or that they think I got wrong, you are welcome to leave a comment ^^’ I’ve done this without thinking too much, but I feel it was necessary. I hope this has helped you to clear your head ^^
- Here is the link to the original post and my addition + other answers alnair-tair.tumblr.com/post/180696016222/clap-with-me