I'm neutral, or more like, "meh" about this. To me it's just another fictional thing in fictional works, it's the constant arguments online that makes it weird (side-eyeing a certain normies game with a pseudo-brother LI...)
In my opinion a lot of fictional media isn't realistic to begin with so there really isn't a need to explain everything. Thought such as
"As soon as the brother thing drops I start thinking about their parent's, how tf are they gonna get married, inbred babies..."
depends on your suspension of disbelief tbh. It's like those yandere/kidnapping games I've seen becoming more popular recently. I have lots of questions to ask when it comes to the realism of those games, how certain situations can be possible etc, but I decide to shut my brain off temporarily for them.
If you really worry about the marriage/baby issues, many otome games end without reaching that stage anyway, so players can ignore it (like an open happy? end kinda thing). And, realistically speaking not all couples will get married and have kids. But I do agree that it would be more interesting if the writers address the societal nuances. It wouldn't magically make an incest hater like incest, but it would at least add some depth to the relationship and story.
At the end of the day, it comes down to different POVs. You think of incest as an important detail that needs to be resolved in the plot, the writers on the other hand just treat it as a trope. "Here's a route where you can get chummy with your hot brother" - that's about it.
Because it's a trope, there's nothing you're "missing" if you don't like it. It's simply personal preferences

As long as you're not shaming people who like this trope in a fictional space, you don't need to get over anything.