Most of revenue for IBM comes from consulting, which needs heavy headcount. Up to 2011 IBM was like a leader in consulting making 100+ billion in revenues a year including all divisions , downfall started after that. It’s not even making half of it now. Accenture/Deloitte and others like Cognizant are eating its lunch.

https://www.macrotrends.net/stocks/stock-comparison?s=revenu... https://www.statista.com/statistics/269013/deloitte-revenue-...