I can understand you wanting to give information, but it was a lot. It’s kind of like going to a restaurant, asking what the special of the day is and then someone giving you the entire menu; it’s nice to know, but you really wanted one specific thing.
Getting back to topic, though, inter-company crossovers are possible, but again they take so much bargaining from both sides. Look at the headache Disney and Sony go through trying to keep Spider-Man in the MCU. In theory it should be a no brainer, but it takes so much negotiation. The only reason they make it work is because they know the audience is there and with the films making so much, they know they can get a big slice of the pie.
Theoretical economics aside, what you’re asking for may be possible one day, but as it stands now, the omniverse you’re looking for remains a fun idea.