High Sierra is objectively snappier on older SATA SSDs. The kernel is lighter without the weight of SwiftUI, Sidecar, or Catalyst frameworks.
Once you download the official Install macOS High Sierra.app , it is best practice to create a bootable USB drive before running the installation. This allows you to perform a clean install if your current OS becomes corrupted. download+macos+high+sierra+10136+exclusive
Apple officially removes older macOS versions from the main App Store storefront over time. However, they maintain hidden "direct links" on their support servers. You do need to visit third-party "exclusive" download sites, which often bundle malware. High Sierra is objectively snappier on older SATA SSDs
High Sierra reached End of Life (EoL) in late 2020 and no longer receives official security updates from Apple. Key Features & Improvements download+macos+high+sierra+10136+exclusive