I think the author missed the point that 45% of Accenture's revenues is from their business process outsourcing activities (e.g. accounts payable processing).
As for the 55% of revenues that come from consulting, I have been a client of Accenture (and other consulting firms). It is very hard for an organization to gear up to replace a large customer billing and information system. The activity happens once every 15 years and may be a very different technology than other solutions deployed in the company.
https://investor.accenture.com/~/media/Files/A/Accenture-IR-...
As for the 55% of revenues that come from consulting, I have been a client of Accenture (and other consulting firms). It is very hard for an organization to gear up to replace a large customer billing and information system. The activity happens once every 15 years and may be a very different technology than other solutions deployed in the company.