"Is the purpose of the form 5498 to let the IRS know that an IRA account was inherited?"
On a Form 5498 from an inherited IRA, both the decedent's name and the beneficiary's name are to be shown in the PARTICIPANT'S name field.
The RMD boxes might indicate that an RMD is required and the amount of the RMD, but IRA custodians are not required to complete this section on Forms 5498 for inherited IRAs. It would typically take an audit by the IRS for the IRS to determine if insufficient RMDs have been taken.
