Ever since the game started there has always been a character who's strength rivals our own, whether it was the white raven, black wolf. Lahabrea, nidhogg or emet selch. But these characters were more of a villain of the expansion than a rival.
In writing, particularly shounen and other superhero media, the single most important character besides the protagonist is the rival. A rivals job is to be just leaning enough to the side of good to help the protagonist, but leaning against good enough to have conflict with them
For some time ffxiv had a rival, and while many don't agree he was good rival (I liked him) he fit almost every criteria needed to be a rival
His strength rivaled our own
He was positioned against us but also against our foe
He pushed our character to greater heights
He understood the wol on a primitive level
He was entertaining and intimidating
Our wol was interested in him all the way through
He is both a friend and an enemy
Now; am I going to say zenos was the PERFECT rival.. of course not. But in the scope of everything we have he might just have been the best thing we had (also we stole his job twice, lol) zenos as a constant lingering threat... even when on our side kept the tension in the game alive aswel as power checking the wol.
And - that's the issue with dt. There is no longer a power check, a morally ambiguous figure or even a real sense of friendly competition. In my honest opinion removing zenos from the msq was a mistake. Because they removed the only thing which grounded the WOL and killed all sense of danger . We Know we're a God slayer, we know we're 7/14ths ascian and that makes us stupidly powerful and we know we can essentially swat anybody who tried to punch up to us. EXCEPT ZENOS. If you think surviving within an inch of our life is something we could do again and again then of course your not looking at the broader picture. We can't just fight zenos whenever we want because we are gonna take a massive hit from it
But if they were to either bring back zenos, or add a new rival it might go some way to rebalancing one of the games more jarring elements right now. A complete lack of tension or personal investment in the story
With how dawntrail is being written, I would not advise creating a new rival, as I feel they might be shallow and un-intimidating . And the zenos minion still isn't out 3 years later either which gives me hope for a retcon on his death