I completely agree with you, but on a side note, you can at least get descriptive text for most Microsoft-defined error codes using

https://www.microsoft.com/en-my/download/details.aspx?id=100...

which effectively looks up error codes in Windows SDK header files (which need not be installed)

  ~> err 0x80070091
  # No results found for hex 0x80070091 / decimal -2147024751
  # as an HRESULT: Severity: FAILURE (1), FACILITY_WIN32 (0x7), Code 0x91
  # for hex 0x91 / decimal 145
    ERROR_DIR_NOT_EMPTY                                            winerror.h
  # The directory is not empty.
  # 1 matches found for "0x80070091"
  
    ~> err 91
  # for decimal 91 / hex 0x5b
    SET_ENV_VAR_FAILED                                             bugcodes.h
    NMERR_DISCARD_FRAME                                            netmon.h
    LDAP_CONNECT_ERROR                                             winldap.h
  # for hex 0x91 / decimal 145
    WIN32K_INIT_OR_RIT_FAILURE                                     bugcodes.h
    ERROR_DIR_NOT_EMPTY                                            winerror.h
  # The directory is not empty.
  # as an HRESULT: Severity: SUCCESS (0), FACILITY_NULL (0x0), Code 0x91
  # for hex 0x91 / decimal 145
    ERROR_DIR_NOT_EMPTY                                            winerror.h
  # The directory is not empty.
  # 6 matches found for "91"

which is frequently better than nothing, grep, or Google, especially for small integer error codes (and, in the case of Google, for any HRESULT Windows Update or the Microsoft Store has ever returned).