Out of curiosity …
Why would this happen even after a full installation?
Mar 30 09:59:45 simplexity2204 systemd[1]: Started MongoDB Database Server.
Mar 30 09:59:45 simplexity2204 systemd[12475]: mongod.service: Failed to locate executable /usr/bin/mongod: No such file or directory
Mar 30 09:59:45 simplexity2204 systemd[12475]: mongod.service: Failed at step EXEC spawning /usr/bin/mongod: No such file or directory