OnyX has not performed any useful functions in nearly two decades. Anything beneficial it was capable of performing in the distant past is now managed by macOS.
You can keep it around as you wish, but I would not trust it any further than I could throw it.
Anyway you piqued my curiosity so I downloaded and ran the latest OnyX version. It also found "94 recognized malware" on this malware-free Mac. All the alleged "malware" it identified were legitimate macOS files or equally legitimate file components.
The plot thickens. Apparently the files it identified as "malware" were signatures of legitimate malware contained in macOS's own Gatekeeper data. macOS keeps a record of known malware so that it can be blocked. That record of known malware is what OnyX found, and erroneously reported as malware.
Excerpted from Gatekeeper and runtime protection in macOS - Apple Support:
... by default all software in macOS is checked for known malicious content the first time it’s opened, regardless of how it arrived on the Mac.
my main question is should i really belief that i has that many malwere.
The answer to that question is no.
After you have been sufficiently entertained by the antiquated "OnyX" app I recommend you drag it to the Trash.