SalesforceDX brings to the Salesforce ecosystem a new way of developing applications on the platform, and using a new form of metadata for that. This new development model is great for CI/CD and testing (with disposable environments).
However I'm having a difficult time on defining who the target audience is. Because every example, every tutorial, every video I've seen so far seems to be focused on teams developing applications to the market.
Everything is great, but how about customers that have highly customized applications, that will not get published (in-house development)? The organization that serves as production environment is also the dev hub? Can scratch orgs replace sandboxes? Will this new model replace the current model that is based on change sets? Can customers who do in-house development benefit from SFDX?