Some more:
I understand XBC2 also has some very complex mechanics that are hard to understand. But the game doesn't force us to understand it if we don't want to. You could finish the game without knowing the battle system deeply. I remember I only really understood the elemental orbs system in the final quarter of the game.
Having not played 2 yet, I'm surprised how complicated and confusing it looks to me, who has beaten every hidden boss in XC1 and XCX. I'm sure I'll be fine. But I've seen videos where there's combat hud data in all 4 corners of the screen, plus the top and the bottom center, with data appearing briefly on the center left and center right of the screen as well, along with the usual numbers appearing over enemies after attacks. It looks totally crazy to me at a glance even compared to other Xenoblades, so I'm glad to hear some people find the combat more accessible. And I expect I'll love it anyway, since it has Elma and overdrive.
But I'm quite attached to the battle interface of XC1 and XCX, the arts palette. It's true that you sometimes have to press a direction 4 times to choose a move, but that doesn't bother me personally - it just seems cleaner and simpler with my big coloured orbs and their cooldowns. You're certainly right that the simple interface belies and lot of complexity and depth that just isn't explained that clearly. That's how it is. Some people are gonna get deep into playing around and figuring things out, some are gonna feel frustrated and confused, and others like me are gonna watch experts explain the nuances of the combat on youtube and be like "ohhh, now I get it."
I hope more people will give the game a try, having only played XC1 and XCX, XC1 looks like the easiest place to learn Xenoblade combat from my perspective.
One thing I'm really excited about trying now, after having gotten my head around the overdrive system in Xenoblade Chronicles X, is playing Definitive Edition and using the chain attack system in a more "overdrivey" way than I did before. To people who haven't played, the chain attack is kind of your limit break, your ultimate move where your party all take turns laying into the enemy. I've used it to great effect before, although I was usually just trying to topple the enemy and then go for whatever quick damage I could. One thing I didn't focus on was the "chain multiplier" aspect of chain attack, which will increase your damage output in a very overdrive like way.
For people who haven't played, all the arts have different colours based on what type of effect they have, as you can see in Danjin's picture. Red arts are pure damage, and blue arts are healing and buffs, etcetera. Every time you use the same colour art sequentially in a chain attack, you increase the chain multiplier, boosting your party's damage output up to a maximum of 700% when you've done 5 arts of the same colour in a row. But that's a bit tricky so I didn't bother to explore it before. You can't use the same art twice, and a well rounded party with support or magic characters would have mostly different coloured arts from the fighters in the party, so it's hard to get 5 arts of the same colour without a very specific setup. But just like we've been saying, the game doesn't explain things super clearly, so I didn't understand back when I played Xenoblade that each character's unique talent art
counts as any colour. Everyone has a personal super art called a talent, like Reyn's mad taunt or Dunban's blossom dance, and they don't just count as any colour, they count as any colour in both directions. So I could start a chain attack with 2 blue buffs that increase my power and give me a x2 chain, use a talent to reach x3, and then switch to doing red battle arts twice to get to x5 and 700% max damage, then obliterate the big monster I'm fighting with my most powerful art for my 6th move.
Knowing this type of thing now, I'm really hype to play XCDE and I can't wait to see what kind of damage I can do even in the early and mid-game. But I imagine I will need some agility gems to hit enemies that are higher level than me and I will need to work on affinity between party members early to increase the chance of extending chain attacks.