Then came Lean and Agile, and Six Sigma lost its limelight. However even the newer concepts of Process Modeling , Design Thinking and Iterative cycles have their roots in Six Sigma methodology.
Over the past decade I have come to realize that no organization / product can grow unless it is backed by sound processes. You can have a terrific product which generates tons of clicks on the Buy button but it all falls through the cracks if your logistics process is not streamlined or customer support process is non existent. Similarly a great new idea might generate publicity and garner eyeballs but if there isn't any process to keep the creativity wheel running - you'll end up with a one idea wonder.
Even a customer journey mapping is essentially process modeling where the data gets transformed into various forms as it traverses the different flows ( login -> searching a catalog -> checkout ).
Process flows - the As-Is and To-Be are crucial to understanding the gaps and where improvement opportunities lie.
So processes can be considered the backbone of the organization and the even though they are the backstage performers, the quality of the product / maturity of the organization will all depend on the how much focus and effort is put on the unsung heroes ( aka processes ).