Because Microsoft said so:
https://learn.microsoft.com/en-us/windows-hardware/design/minimum/supported/windows-11-supported-intel-processors
In case you want to know specifics, there are features missing on your processor, the most important of which is VBS (Virtualization based security). Now, if you really want to run W11, you can. However, you are without support.
Doc (not an Intel employee or contractor)
[Maybe Windows 12 will be better]
