For real tho, I get that everyone hates the Palace and that's perfectly fair. Look at the broader picture tho.
Battle Tower - Absolute CLASSIC. BDSP had a great one with the Gym Leaders showing up, and SwSh's was bashed for being worse than the standard. Hasn't really been missing in most 3D games, so it hardly counts.
Battle Factory - Another classic, great gateway for the rest, and just a ton of fun with crazy variance to keep anyone on their toes.
Battle Dome - Underrated gem, I really wish it was closer to VGC/Stadium settings instead of Take 3, Pick 2 in Singles and whatever in Doubles, I'm going off memory here. Apparently, it was one of the easiest, but I'd guess it's because you had so much information. Fair enough, I guess. Still really fun and it was interesting to see the other brackets. My personal favorite tied with the Factory.
Battle Pyramid - Very unique facility, great idea, and I'd really wish to see it back in an expanded, more interesting format.
Battle Pike - Also underrated, but it was great. I'm still mad they had wild Milotic, but I couldn't catch one.
Battle Arena - An interesting facility because it requires a different team composition, but it only really shines at higher streaks. Early streaks kind of break the gimmick because you can easily 2~3HKO a Jigglypuff lmao.
Battle Palace - I think everyone agrees this place is a hellhole, designed by the same people that made DP's Great Marsh. Probably programmed by Masuda himself. Fuck this place with a rusty rake.
Gen 4's Frontier was aggressively mid, but the Castle was really fun, the Hall was boring, but not that bad, and the Arcade might as well be russian roulette, but your opponent gets the first 4 shots.
And it says a lot I remember all of these without checking Bulbapedia for how they work.
(I barely remember the Hall tho, I only remember it's 1v1 and there were ranks based on types)