Centreon is part of the Nagios ecosystem, meaning there is a huge number of resources you may find around in the community (plugins, skills, addons). Zabbix monitoring paradigms are totally different from Centreon. Centreon plugins have some kind of intelligence when they are launched, where Zabbix monitoring rules are configured centrally with the raw data collected. Testing both will help you understand :)
Users used to say Centreon may be faster for setup and deployment. And in the end, both are full of monitoring features. Centreon has out of the box a full catalog of probes from cloud to the edge https://www.centreon.com/en/plugins-pack-list/
As soon as you have defined your monitoring policies and template, you can deploy it fast through command line API or REST API.
Centreon plays well in the ITSM, Automation, AIOps spaces with many connectors for Prometheus, ServiceNow, GLPI, Ansible, Chef, Splunk, ...
The polling server mode is one of the differentiators with Centreon. You set up remote server(s) and chose btw multiple information-exchange mechanisms. Powerful and resilient for remote, VPN, DMZ, satellite networks.
Centreon is a good value for price to do a data collection (availability, performance, fault) on a wide range of technologies (physical, legacy, cloud). There are pro support and enterprise version with dashboards and reporting.
IT Central Station gathers many user feedback you can rely on both Centreon & Zabbix https://www.itcentralstation.com/products/centreon-reviews