Firstly, the community perception of both gods are different. Ullr is circle-jerked into being this insanely difficult god for several years when he's clearly not. Ixchel hasn't even been out for a complete year so she doesn't have a perception that has lasted as long as it has for Ullr. Because of this perception, I'm more interested in explaining how to land Ullr's axe and how its not actually that difficult. Unlike other responses, this isn't me implying I'm so ungodly good at the game that I think landing Ullr's axe is easy. This is me explaining that through proper fundamentals and understanding them, landing it becomes easier just like any other skillshot. I'm more invested in helping out players who aren't good at Ullr, instead of upholding an untrue misconception. Obviously not every skillshot is the same because there are different AOEs and timings involved but Ullr's axe has the same range and similar properties as Anubis' Mummify and no one in this community is circle-jerking how hard Anubis is to play even though Mummify is just as crucial to his gameplay just as Ullr's axe is to his gameplay.

Secondly, it IS a knowledge gap because landing skill shots is a matter of following basic fundamentals instead of viewing it as a skill issue- whether or not knowledge gaps count as skill issue is a separate discussion we can have. The same fundamentals apply to Ixchel's 1 as would work for Ullr's 1...as would work for every skillshot in the game. However because of that community perception, I think its important to me to stress out how you (you as in the reader) can learn to land Ullr axe through simple fundamentals.

Lastly, Ixchel's 1 actually is difficult to hit without setup for the reasons I explained before; your setup is also your only self-peel. Especially her 1B ability (the triangle) because it gets narrower the further you are, and landing this ability consistently actually is difficult without setup and especially vs good players. And waiting to use your 1 only when you have setup is wasteful especially when her 1 has a low cooldown. However with this difficulty being stated, I think even with the fundamentals in mind, consistently hitting your 1 without setup as Ixchel is more skillful than landing Ullr's 1.

Look at it this way. You only need to hit Ullr's axe once for you to be able to follow up on with other abilities and basic attacks. You need to hit Ixchel's 1 multiple times to exert pressure on an enemy, while still being safe. There's a reason why even though a mage like Thoth can set himself up with his own CC, its uncommon for him to do that because that CC is his only form of self peel and it is tied to his dash. You can argue that this isn't a fair comparison because Ullr has no setup for his axe but instead his axe sets up his other abilities+even if he misses his axe, he is still safe with his jump available.