Whois data is not identical for every extension. Each registry defines its own rules, format and privacy policy, and many have moved part of the data to RDAP.
For .com and .net domains, the registrar usually plays an important role in the displayed data. For country-code extensions such as .it or .eu, the local registry rules determine what is visible and how expiration or status information is reported.
Some extensions show detailed dates and statuses, while others hide registrant information or provide only technical data. This is normal and does not necessarily mean that the domain is problematic.
When checking a domain, compare the Whois or RDAP output with other signals such as DNS records, archived website snapshots and marketplace history.