Compared with reseller stacks
Most agencies selling "their" platform are licensing one and putting a logo on it. We did that first, wrote down what it could not do, and then built this. That list is the comparison.
Whose roadmap
A reseller cannot ship a fix. They can file a request. When the thing you need is a data model change, the answer is a workaround, and the workaround becomes how your business runs.
The database, the API and the migrations here are ours. That is not a marketing point in itself; it is the reason every other point below is possible.
Whose outage
When the licensed platform is down, the reseller writes the same status update you could have read upstream. The incident is not theirs to work.
How far the branding actually goes
Reseller white-labelling stops where the licence stops. There is usually a surface - a transactional email, a mobile app, an assistant name - that stays theirs and reappears after an update.
Ours goes to the assistant name, because the persona is a field we own. See white-label.
What the isolation story is
Ask a reseller how tenant data is separated and the honest answer is that they do not know, because it is not their database. Ours is enforced at the database layer rather than by application code, and we publish the mechanism on the security page rather than describing it in adjectives.
Where a reseller is the better choice
If you want to be selling next month rather than next quarter, a reseller stack is faster to stand up and there is a large ecosystem of people who already know it. That is a real advantage and we are not going to pretend otherwise.
See what a native build changes
Bring the workaround you are living with. That is the fastest way to find out whether this is different.