The actual buyers of payroll software don't care and if you think people are going to evaluate their potential employer based on what payroll solution they use, you are wrong.
This may not be correct. My current company uses Gusto for payroll. Pulling my data, I see everything. I am confirming with Gusto support its sourced from them.
Confirmed with Gusto. They send data to WorkNumber.
"...for the purpose of automating employment and income verifications. This feature helps streamline the process for employees who may need to provide proof of employment or income for loans, credit, or public aid."