Like a lot of stuff on this forum, the OP contains both questions and answers in the same posting. Why does Accenture add value to its business year after year and IBM (and now Kyndryl) does not?
Answer: Accenture adds value to its offerings because it chooses to, and it represents itself to its customers as both business consultants and IT consultants at the same time. Accenture's peers (competitors) in the market are Deloitte, IBM (Consulting) and Capgemini, among others.
IBM (GTS) and now Kyndryl were structured as strictly IT and not business consultants. This is obviously an oversimplification, but the bottom line remains...Kyndryl is treated by the market as an IT body shop, because that's how the business is presented. It's competitors in the space are Wipro and Tata, among others.
Have you ever sat in on a client-side negotiation with Accenture and/or IBM and/or Kyndryl? I have. IBM GTS (and probably now Kyndryl) focuses the discussion on specific IT services (help desk, system admin, DBA, network, system builds, etc.), their HR requirements, and prices. The negotiators meet with the client, go back to their hotel rooms and play with spreadsheets, then go back and forth with the client until a deal is made. It's basically a matter of cost, profit and loss. How much will IBM (and now Kyndryl) spend on service delivery (which may in fact be totally erroneous, by the way), and what will the P+L be on this deal?
Contrast this with a discussion with Accenture. Sure, Accenture will do a negotiation like IBM/Kyndryl if that's what the customer wants. However, customers do not approach Accenture as just an IT body shop. They expect Accenture to be experts in both business and IT. Instead of a plain ole DBA, for example, they expect that DBA to give helpful assistance to the business that might help them work more efficiently or to save money. It's a level of service (and therefore value) that was never expected from IBM (at least on the GTS side of things).
Could IBM have worked differently by combining GTS and Consulting? I dunno...it could have happened I suppose, but it didn't work that way when I was there. Consulting and managed services were always handled separately. Maybe Kyndryl can change that approach...it would certainly help them add value to their offerings.