Whether MDM is dead depends on its data quality. Should you search on a current MDM and retrieve the 100th customer information, you very well may think MDM is dead.
If you must resolve that type of wrong data manually before running any customer and product reports, you will likely go back to your Excel spreadsheets. That way, you can at least standardize your data.
But many a business swears by their MDM system as a valuable tool, shared and used among many organizational processes. A Valuates Report projected the MDM marketplace to grow to 17880 million USD.
So, a useful MDM is worth its weight in gold.