@cj Isn't that essentially the whole point of rebadging employees to companies like Infinite? Fiserv is deliberately moving those employees off its direct payroll and shifting the cost of performing that work to an outsourcing contract. The idea is to reduce costs, transfer employment responsibilities to the vendor and give Fiserv more flexibility in how that work is staffed. Sure outsourced employees still represent a cost to Fiserv and those contracts absolutely should be evaluated for productivity, performance, value etc but I think you're looking at this primarily as a question of individual employee performance when management is making decisions about which functions it wants to keep in house versus outsource. Even if a long tenured Fiserv employee is more experienced or productive than someone working for Infinite, mgmt may still prefer the outsourced arrangement if it believes the total cost of delivering that service is lower.
The bigger question IMO is whether Fiserv is actually realizing meaningful savings from these decisions once you account for lost institutional knowledge, reduced productivity, service quality, additional work being absorbed by remaining employees etc. Eliminating positions might look good on a spreadsheet but that doesn't mean the company is operating more efficiently.