Reselling through ProAdvisor pricing
Intuit’s ProAdvisor preferred pricing lets a firm receive a discount on client subscriptions when the firm is billed for them. The firm can then include the software in its own fees. QuickBooks does not offer a white-label version, so clients always see the QuickBooks brand.
This is an established and well-understood model. Clients know the product, staff are often trained on it, and many apps connect to it. Firms that value that familiarity have good reasons to continue. Nothing about a white-label ledger requires abandoning that setup for existing clients.