How else do you fund such a horrendously difficult thing? There is a reason there are no other cross platform UIs that are QT’s equal. Creating a good looking cross platform UI that supports things like accessibility and provides a close to native app experience (or can) is a real slog of a programming project. It must also be constantly maintained as native APIs change out from under it, hardware advances (e.g. higher DPI displays, HDR), and UI trends change.

Pay for Qt or pay for developer time to maintain multiple versions of your UI. Your pick. Qt is probably cheaper in most cases.