Standard ISOs often lack the directory structure needed for UEFI booting from a USB.
Head to a reliable source for Microsoft ISOs (like HeiDoc Windows ISO Downloader or the Internet Archive) to grab the official Windows 7 SP1 ISO.
Let’s be realistic. Microsoft ended Extended Security Updates (ESU) for Windows 7 in January 2023. Running Windows 7 on a modern UEFI machine means: