This is the point that always gets lost in THAC0 arguments. They often come down to trying to measure just how difficult/easy or complex it was to actually deal with in play, which is a deeply subjective sliding scale that people are, very understandably, not going to agree on. It's not even a worthwhile argument to have, honestly.
But there are things which we can say are objectively true, or are at least closer to an objective truth than not. For instance, I grew up with 2e, played it for years, spent many years consulting the THAC0 tables, etc. So when I say that I say that the weapon type modifiers for armor in the item descriptions in the Baldur's Gate games constantly confused me, for instance, it is not a function of the difficulty or complexity of the system, but because of how unintuitive it was.
Whether you found THAC0 and descending ACs easy or difficult, complex or easily solvable, is a matter of personal experience, skill, knowledge, etc. You can argue that it wasn't that complicated. But you cannot argue that it was intuitive.