If you are looking at a specific report for a "Modern XP" build, it likely features:
Integration of the "Simplix" update pack, which streamlines the installation of hundreds of post-SP3 fixes. Windows XP Professional SP3 Dec 2021
A December 2021 GitHub repository tracks the "latest" software still compatible with XP, such as the MyPal Browser (a Firefox fork) and specific versions of VLC and Notepad++. If you are looking at a specific report
Reports highlight the use of custom drivers to enable XP on modern systems, including support for SATA/AHCI , USB 3.0 , and even NVMe SSDs . including support for SATA/AHCI