Anime is a product made by large teams of skilled workers.
The people who make it have to work as a large team with a high level of conformity to recognizable stereotypes.
2D yuri is a highly recognizable stereotype. Just as a manufacturer might skimp on quality by adding a low-cost component, anime makers can skimp on quality by adding yuri elements.
(Consider, for example Psycho-PASS. It had lesbians, but their lesbianism was pointless stereotyping that added nothing of value.)
In most cases, throwing yuri into an anime plot is like throwing sawdust into bread dough. It makes a product that the consumers will accept, but it adds no value.
In some cases, celebrating unrealistic perversion adds some kind of marginal value, but it usually just allows a combat-fantasy to do double duty as a porn fantasy. One example of this is Otome Youkai Zakuro, which features three characters who have an unrealistically affectionate and long-lasting menage a trois.
In real life, a menage a trois is likely to be driven by short-term lust; it is not likely to be driven by emotional attachment, and is not likely to last for a long time. Although the example cited managed to break new ground with this unrealistic fantasy, it doesn’t deliver anything meaningful.
The people who made the show knew that their largest audience segment was composed of heterosexual men who liked magical combat and male-female-female menages. The creators proved that they could pander to both desires of that audience with a single show. But the result was just pandering.
By contrast, a show like Natsume’s Book of Friends does teach a little something about how boys can grow up by avoiding unwinnable fights, relying on protectors, and eventually growing stronger. It’s probably not great literature, but it teaches a few lessons that are applicable to real life.