Well, the Apollo program ended in 1972.
You are right that some documents, telemetry, and video footage were lost due to government incompetence...sorry, to "regain storage space", though.
All of the Saturn people were still there. Skylab was placed in orbit using a Saturn V, and the Apollo was used to transport astronauts there and back.
At the time I was there all Saturn/Apollo documentation was in the documentation center. I retrieved quite a lot of material from that facility.
The government made a choice to discard documentation, as did the numerous contractors. Nothing was lost due to incompetence by that generation. I can't speak for the youngsters who followed.
All of the telemetry was stored on 9-track magnetic tape. There were large rooms with large shelves for them. The base material did not stand the test of time; and, 9-track tape transport machines eventually degraded beyond the scope of routine maintenance. Neither tape or the machines are made at this time; and, few machines work.
My job at Marshall was "data reduction". I wrote software for that purpose and handled a lifetime of 9-track tapes. Remember: "No ring, no write".