Xenogears has the incredible gift of being mostly free of the most cringey Japanese tropes and managing to be actually, undisputably adult in some key moments.
It’s easy to point out the mishmash of western religious themes and laugh at almost inevitable characters like Maria and Chu-Chu, but you don’t need to look that far beyond those to see some amazingly solid dialogue and characters. Citan is one of the best video game characters ever written. The game develops its themes in a very realistic way, despite being pure fantasy. Xenogears is leagues better than the work it clearly homages - Evangelion wishes it was as accomplished and comprehensible as Xenogears, and it’s only because the two works belong to such different mediums that Evangelion made it into legend while XG is today a relatively unknown cult game. I’ve never seen another game try the same without inevitably falling foul of anime tropes, excessively convoluted telling, and bad dialogue and design; Chrono Cross probably flew almost as high, but it doesn’t cut as deep. God bless the incomparable freedom devs had at the time.