I believe you have an SSD failure due to this listed in the Kernel Panic:
ANS2 Recoverable Panic - assert failed: [19346]:apcie0[0]: PCI device failed to resume
Most SSD failures occur when first powering on the SSD or when waking from sleep. Everything you have described, along with this part of the Kernel Panic seems to be consistent with an SSD failure.
Plus the Logic Boards for the MBPro 16" (2019) model have an extremely high rate of failure. In fact, I have seen multiple forum posts recently where people have mentioned receiving bad Logic Boards from Apple when they had their MBPro 16" (2019) laptop's repaired by Apple...some have said the 2nd replacement Logic Board had issues as well.
Personally I would advise against spending any money to repair any of the Apple USB-C Intel Macs for multiple reasons, but especially this specific model. The money spent on repairs would be better spent going towards a new replacement laptop instead.
I hope you have a good backup of your computer since the SSD could fail at any time. If the laptop boots to a blinking folder with a question mark, then try Option Booting by holding the Option key immediately after hearing the startup chime....this may be the SSD enough time to power up & go ready so that you can boot the laptop, but this is only a stop gap measure.
People should always have frequent and regular backups of their computer and all external media (including the cloud) which contains important & unique data. There are a lot more new ways to permanently lose access to the data on the internal SSD of these recent Macs due to all the hardware, software, and security changes. With the 2018+ models with the security enclave chip, the chance of recovering data is nearly zero even with an expensive professional data recovery service.
