It depends on your meaning by "salesmen", but in many cases in the modern enterprise ("account executives"), they're basically glorified customer support positions that get paid for retaining the customer and the ability to upsell. Same thing you get when you call the support line, except an account executive has a handful of customers to whom he is dedicated.
If you're talking about sales that functions primarily as new customer intake and has no long-lasting relationship with the clients, like door-to-door sales, I can see a better argument for that going obsolete.
If you're talking about sales that functions primarily as new customer intake and has no long-lasting relationship with the clients, like door-to-door sales, I can see a better argument for that going obsolete.