is sentinel one necessary to Mac Sonoma 14.0 ?

Refer to an older posting for an older version of macOS

The principal applies for any version of macOS including Sonoma

AntiVirus Sentinel Pro - Apple Community

Specifically refer to posting by @ Allan Eckert

There are no known Windows-like Viruses in the wild that self replicate and affect macOS, because of the underling UNIX  Foundation and Permission Limitation. 

The Operating System resides in a Sealed and Read Only Volume that can not be opened by the User nor by Third Party Applications.

The only Entity that can open and modify or alter this Volume is Apple.

That would occur when a update or UpGrade is performed.

The Only thing this Antivirus software is protecting is the Bank Account of the Developers and for zero return to the User aside from the problems this software creates.

AntiVirus Developers purposefully Market their product to create a “ Fear Factor “. In so doing, creating a False Need for their Product.

kicoyuri wrote:

is sentinel one necessary to Mac Sonoma 14.0 ?

I was advised for the first time of a Trojan in my Computer when I have installed Mac Sonoma 14.) in a new Macbook

No.

Third party AntiVirus is not recommended— it typically does nothing but add issues to the macOS and competes directly with Apple’s own built in security:

macOS - Security - Apple macOS - Security - Apple

Apple Platform Security - Apple Apple Platform Security - Apple Support