SELinux has rules to filter out – to not log – some messages. You can disable them to get more:
The journalctl shows all logs if you don’t limit it to specific unit. (It shows with pager – less – so one could search, or grep the output. If you have a word to look for.)
The systemd-journald keeps logs in memory, unless told to write them to files too. Whether in RAM or files, the journalctl is the tool to read.
If rsyslog is installed, then it will write to the “old format”, to /var/log/ files. (IIRC, it now gets data from systemd-journald.)
Early version of CentOS/Alma 8 did not install rsyslog in “Minimal environment”. These days it does get installed.