Apple no longer shows High Sierra in the "Featured" section of the App Store. However, they keep a hidden, official URL alive for legacy support.
Need the direct Apple Support link? Search for "Apple HT208969" and you’ve found the golden source.
In the world of macOS, High Sierra (10.13.6) holds a unique and important place. It is the final operating system for many beloved 2010-era Macs (like the white unibody MacBook and the classic Mac Pro 5,1). It is also the last version to support 32-bit applications without compromise.