A company has an obligation to protect their customers' data, due to GDPR and a variety of other privacy rules. If one of their people - employee or contractor - has access to customer data, the company must mitigate it being stolen. In an office environment, they could do that by limiting personal devices, barring notes and other information going out.
When these positions become WFH - even with a company owned/managed device - they have an entire new class of threats to mitigate: personal devices, shoulder surfing, etc by not the employee but someone standing next to them.
While I hate the surveillance aspects, I want my account information protected and I don't see a better approach in an uncontrolled/unknowable environment.