Usin a tag does not exclude the other games. It just includes games where the developer had the opinion the tag would apply. Some spam their tags, some use it specifically. Should they tag lesbian in addition to yuri? Should they tag lgbt too? Or lgbtqia+ or any other inflationary letter combination someone out there uses?
In theory there could be a tag hirarchy. Like, all yuri games have lesbian content by defintion. All psycholocial horror games have horror by definition and so on.
Or a set of core tags that get aliased in behind the scenes. Like all survival horror games having the hidden tag horror as well.
Problem is, that tags are not really curated. Neither their existence, nor their usage. It is open tagging. People use tags they know and think have a certain meaning. Some would tag lesbian and anime, others only yuri. Which is correct?
As long as tags are developer chosen, there is not much that can be done here.
Let's look at Steam, for lack of sites with game tags (actually there are not really any. Not sites that do host games. Maybe some forums, but not the game hosting sites). They have a single lgtb tag. One. Only one. They do not have a gay tag, nor a lesbian tag, and absoluteliy no yuri tag. Is this any better? Should people looking for bara be confronted with yuri?
Maybe the reasons are in the information the tags convey. Especially on steam and their fixed set of available tags. They tag more the surroundings and not the content of the game. They would tag a yuri platformer as platformer first.
(Oh, and exlusion of yuri is what you want to do, if you select bara and vice versa. Or maybe I misunderstood because of translation issues.)