The folks in government that design and maintain the servers that provide the service are at the mercy of the lowest bidder. This means changes in hardware, virtualization, subsystems & cloud provider can happen each fiscal year. If some backend software stops getting security updates, rapid changes are needed to prevent cybersecurity incidents. This means affected public-facing applications may need to end and some sort of replacement put in place. The people that maintain these systems dont want to see any changes just as much as you do. Status Quo is Golden.
If you dont want to login every 5 minutes to track your USPS packages, I have a work-around that works in the USPS Mobile app thats available at Apples App Store. Login to Informed Delivery to obtain a Tracking Number and copy it. Then switch into the Track section and paste that number. It creates an entry thats saved in the apps Track section and does not require any login to view. (This is exactly what I do). I dont know if this work-around works inside a web browser. But its something, and something is better than nothing.
DeJoy destroyed the best postal system on earth and we all suffer the consequences daily. But dont assume that a web app changing or disappearing is intentional malice. 99% of the time, its a change due to being forced to deal with a software vulnerability. These systems are complex and consist of hundreds or thousands of software components. IT teams needs to constantly keep on top of *each* components vulnerability status and remediate ASAP to avoid a newsworthy cybersecurity incident. (The time between when a vulnerability is announced to when it is actively bring exploited on systems is a matter of hours, so simply checking once a day is not sufficient. The folks that do this work are unsung heroes because if they do their job right, youll never know about it)