Acting like stories can't be used to examine and consider how we view ourselves and the people & world around us feels like a profound misunderstanding of the purpose of storytelling.
And why do you see it as Otakei being Tsubaki's "second choice"? They drifted apart after high school and weren't in one another's lives until the events that began this actual manga. Where does that make him her "second choice" in any of this?
The author has a setup they're going for, and it involves Otakei overcoming his personal character challenges, and someone who cheered for him back in high school has shown up at a pivotal moment in his life when he's about to have another go at his making his passion a reality.
You say he "can't get a win", and yet he's literally on his way to re-debut his manga work. A rather common storywriting refrain is character who is down-and-out and at the bottom of the narrative pit, and now has to claw their way out to get the wins they didn't have before. Acting like it's suddenly the worst thing here, while relating directly to the FL having had a prior relationship, feels very suspicious, given how much that sentiment rhymes with rather misogynistic rhetoric.
Tsubaki had a direct hand in encouraging him to do so. He's not overcome every obstacle, but it's also, like, the start of the story still, so there's gonna be more to come for him to work through. All of his "wins" are in the future tense, and I would expect that includes a deeper relationship with Tsubaki.
And hell, I'll ask you the inverse: would you be this bent out of shape if Otakei were the one who was widowed, and Tsubaki was single and re-entering his life? It's the same disparity, just in the other direction, so the same inequality in their lived experience should be just as objectionable, right?
