So battery if handled properly will last a very long time. So while battery issues can't be dismissed, at least it often can be replaced or otherwise worked around. The bigger issue is storage errors and being permanently locked out.
The Google Pixel 3 phone he bought died after 2 years due to the operating system not properly handling errors in the non-volatile storage, which is a very common error in Pixel 3/3XL/4 and maybe future ones as well. Google doesn't offer the firehose so owners are out of luck not able to reformat or recover the phones at all and completely locked out by the qualcomm bootloader with phones stuck in EDL mode.
Google Pixel 3 EDL to see how prevalent the problem is, and google just doesn't care to help people fix the issue.