Can't specify font for custom style

#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QFontDatabase>
#include <QDebug>

int main(int argc, char *argv[])
{
    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);

    QGuiApplication app(argc, argv);

    const int fontId = QFontDatabase::addApplicationFont(":/Swis721 Cn BT D-Type.ttf");
    if (fontId == -1) {
        qWarning() << "Failed to load application font!";
    } else {
        QFont font("Swis721 Cn BT D-Type", 10);
        QGuiApplication::setFont(font);
    }

    QQmlApplicationEngine engine;
    engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
    if (engine.rootObjects().isEmpty())
        return -1;

    return app.exec();
}

import QtQuick 2.9
import QtQuick.Templates 2.2 as T

T.Button {
    id: control
    implicitWidth: 200
    implicitHeight: 40

    contentItem: Text {
        text: control.text
        font: control.font
        color: "white"
    }

    background: Rectangle {
        color: "#444"
    }
}