One of the key points to think about here is that not all transport nodes need to store all identity information, attestations and revocations for all users all the time.
With what I'm working towards, you basically only need to store the information for the identities you care about yourself, and when you need information about a new identity, it can be queried from the network, if anyone has it.
If you care about having particular identity information available to the network, you can make your own instance deploy it periodically, or just when you're using a particular application tied to that identity anyway, and let the network cache it in the meantime.