Taking an initiative level as an example, for initial estimates you can view the capacity planning based on allocation across teams, you can further allocate to individual/s within that team if you know who will be working on the initiative.
Once you have a detailed estimate, the look through to individual level is no longer available and all of the time allocated to the initiative will go to the team that the owner of the initiative is assigned too.
When viewing capacity planning we use initial estimates to support future planning and detailed estimates to manage capacity for projects in flight.
We need the functionality available to sync so that we can view both together to get a holistic view of overall capacity.