It's just aa convoluted. I work for Workday. Having to re-enter your data each and every time is part of the enterprise tenant isolation model. There is no information sharing between tenants, especially PII. The UX suffers because of data privacy.
Yea, but companies will keep using it because offloading all HRMS to workday (or similar competitors) is cheaper than doing it all in house. (For companies of a sufficient size. Small enough and it's probably not worth it)