default or selected kernelversion does not have config value CONFIG_IWLWIFI_LEGACY_DEBUGFS.
Result is shown for kernelversion 6.2.5

4965 and 3945 debugfs support


Linux Kernel Configuration
└─>Device Drivers
└─>Network device support
└─>Wireless LAN
└─>Debugging Options
└─>4965 and 3945 debugfs support
In linux kernel since version 2.6.39 (release Date: 2011-05-18)  
Enable creation of debugfs files for the iwlwifilegacy drivers. This
is a low-impact option that allows getting insight into the
driver's state at runtime.