It feels closer to using software than using a website
A lot of online PDF tools feel like a small negotiation every time you use them. Upload the file, wait for it to process, hope there is no limit, then figure out whether the feature you need is part of the free flow or not. paperkit is meant to feel much simpler than that.
You open a tool, work on the file locally, and download the result. That is the whole idea. For most people, that feels more natural and easier to trust, especially when the file is a contract, bank statement, signed document, or something you would rather not send around.