Meta Technical Sourcer interview questions

An R4R recruiter reached out to me on LinkedIn, there were a couple of phone screens followed by a prep call and then 3, 1/2 hour peer interviews (virtual). The entire process took about a month. The prep wasn't entirely relevant--no one asked any questions about sourcing process/methodology, metrics or KPI's, candidate engagement, or taking initiative (all of those appeared in the prep call/materials, but not one interviewer asked any questions related to those things). I was prepped to expect that each 1/2 hour interview would cover a specific area of focus... however, each interview was almost identical, felt redundant, and all three were focused on collaboration and "challenges". There's a good deal of technical skill involved in sourcing that goes beyond interpersonal... critical thinking, analytical, the ability to research and organize information... my expectation of a company the size of Meta (not to mention their visibility in the global tech community) would be to vet those things in an interview, but each interviewer asked the same two (interpersonal) questions re collaboration and "challenges". For all the process and prep, the interviews themselves seemed extremely "lightweight"--lacking in any kind of substance. No one in the process gave me any sense of what it would be like to work there, or why I would want to leave for my current role to work at Meta. Upon completion, when it was decided they weren't going to move me forward in the process... I received a boilerplate email with the statement that they "couldn't provide feedback for compliance reasons". That was most disappointing. As a passive candidate, taking time out of my work schedule to go through the process... they couldn't be bothered to pick up the phone and tell me that?