You fanbois don't understand the business end of it. The third party service has been around since '17 or '18 and has shown little growth.
The allure of it is that it's so much cheaper than UPS/FedEx. To grow the service at those prices, they'll have to hire more people. To keep turnover at a manageable rate, they'll have to pay wages that are competitive with FedEx. If they pay more competitive wages, then the bottom line shrinks. To keep from shrinking the bottom line, they would have to charge higher rates, which would reduce the price advantage they have over other carriers.
You act as though they can charge any rate they want, pay any wage they want, and the magic will simply happen. It surely hasn't as of yet.