It is unnecessarily complicated to have to first create an organization because creating a shared collection.
It would be far easier to create collections and share it with other users. Teams that need more granularity, with several collections and different access levels for each, would still be able to create organizations
This is because sharing collections is paid feature. Namely: You can create organization and share with only 1 person (for free).
If you want to share your collections with more people, you would have to either purchase Family package or Team/Enterprise package.
But I totally understand what you mean. However, when you share collection, it no longer belongs to “you”. So it has to be accessible/manageable somewhere. This is where the Organization feature comes in - you own it, so you control who has access and what is shared there.