Why not making Halion SE more open?

I don’t know why steinberg does not make Halion SE more open, for example support for 3rd party instruments or even loading of e.g. sfz instruments.
Rather obviously Halion (SE) is like a Kontakt (Player), but very obviously Kontakt “won” regarding 3rd party sample libraries. There are 100dreds for Kontakt, way fewer for Halion.
But Halion already lost years ago, but recently something changed, because larger vendors of sample libraries now have their own samplers. E.g. spitfire audio. I assume this is the case, because a Kontakt instrument requires a license to be used with the Kontakt Player ( maybe also with Kontakt Full for best integration ). I don’t have Halion 6, but think the same would be possible there, because a listed feature is the creation of multi-sample instruments.
Sure there might be no obvious benefit for steinberg directly, but indirectly it is again obvious. More users for Halion SE as a sfz sampler for example is at least a user more. And for users it might be an advantage to use Halion SE instead of one of the free sfz sampler vsts. Some might be willing to look for some paid instruments for Halion SE even. Who knows. So i wonder why is this potential of Halion SE not used? Yes it’s UI might need a refresh, well. If Halion SE and it’s library remains as it is, it will be probably not a Cubase feature any new ( or old ) user is interested in. I mean and can only speak of Cubase Element here, but while its content is ahead of Komplete Free. It is not that far ahead. And not even Cubase Pro includes Halion Full, so meanwhile other DAWs have better integrated multi samplers at least in the largest version.
Ok the reason for all this might be, that Halion is in a maintenance mode only, but this seems a strange strategy unless there will be one day a Sampler Track in Cubase which supports multi-samples.

There are many. Maybe I don’t understand what you’re saying.

The few I have show up there: Sonic Atoms and Soundiron

…and there’s a whole host of them on the website Virtual Instruments & Sample Libraries | Steinberg

Maybe i didn’t wrote this clearly. I don’t mean that there are none and one can even argue that there are “enough” for any purpose. But i think even if one only counts NI vs. steinberg, then Kontakt has more. And with the 3rd party i estimate that Kontakt has 10x to 100x more. And choice matters of course, at least for trivial things like price e.g. For sure the even free LoFi Piano is very nice, i like it. But i wonder how many users it has. How many don’t know about it because they don’t have a Halion SE ? And how many users it would have if it were a Kontakt Player library? To make it short i don’t get the steinberg marketing strategy here. They have a product. They have some market share, too. But it is limited to Cubase, Nuendo or Dorico users. And as far as i know the number of Cubase users compared to other DAWs is shrinking. I understand it partially, but partially not. ( e.g. for Cubasis i think it was a good decision not to have audio events and audio parts and i don’t know where this comes from historically. I know no other DAW with this additional distinction, while the underlying concept of recordings and virtual audio clips is the same everywhere i think. Unfortunately Cubasis has still way more bugs. )