Way to much data and matomo Cron tab doesn't have enough memory

Did you enable the DBStats core plugin?

Personally, I run the archive CRON (and all thing that is not directly tracking) on a separate server (then I have 2 servers for tracking and one for archive-CRON + management +…)
Also I configured:

–php-cli-options="-d memory_limit=3G"

See: