[zelphirkalt]

I think you've got a good point there. It would be good to come together at a table and discuss such things on an eye to eye level, between entities. Obviously not always possible for natural persons to all come together. Announcing things well ahead of time can go a long way, rather than suddenly dropping support from one day to the next.

What I would proprose then is, that companies should state their minimum security requirements to work with any other entity somewhere publicly available, so that it will not be something ad-hoc invented for some entity.

I have seen companies trying to treat smaller ones like some kind of supplicant entity, that one can push around and ask about interna, that could easily lead to the bigger company building a copy of the smaller company in a few months, since they got much more workforce to put to it, if they really wanted. Asking for things like "architecture diagrams". I am quite sure, that big companies will laugh you out of the room, if you asked them to provide same for their architecture.