Looks like Apple's "Not A Regression" policy on bugs has resulted in a climax of catalina crashes triggered by the introduction of Sidecar, resulting in an inability to sell a macbook that doesn't restart or batteries don't explode.
Piling bugs have actually created a background overhead and array of reasons for the OS to crash, usually surrounding new features like the T2 chip.
Unfortunately on a system such as the macbook pro 2019 16" and perhaps 13", an OS downgrade isn't possible. Since Sidecar was deemed more important than Stability and a lack of regressive bugs, the reaction is to for people to keep returning these things, even though it is not the hardware, it is catalina.
You can't really blame users for refunding either, they have a 14 day not satisfied return window, or a 30 day defective return window. Due to bugs in catalina, the defects become harder to spot, so users with truly defective units that decide to hold on to their macbook perceiving these crashes all to be catalina bugs, end up holding on to a defective unit.
Hopefully apple's hardware quality in these new macbooks is better than the software...still unable to do much on mine apart from use a tiny set of software, but my 2016 13" macbook pro with catalina is doing a whole heap of things and not crashing. The freeze and restart seems to follow a gpu switch.