Yeah I've got to agree with this. Spent a chunk of yesterday looking at Download bills from recent years, and ATDR/Frank Carter/Gojira/Rise Against are such profoundly more exciting acts to have on main than, idk, Slash, Thirty Seconds to Mars and Black Stone Cherry. And if you're going to have subs from the 90s, Deftones and Korn are as strong and legit as you can get.
And yes, the headliners this year leave a lot to be desired. KISS can do one, Biffy are a hard sell to the faithful and SOAD don't have their heart in it, sadly. It's a weaker than average trio on the face of it, for reasons. But the undercard is great.
There's so much bloat with the heritage hard rock/metal that Download relies on, and 2021 has a good amount of bite instead. Got to respect it and look to the future.