While the final release of .NET 8 happened in 2023, the seeds were planted in 2021. During this period, Microsoft was finalizing the transition from ".NET Framework" (the old, Windows-only version) to ".NET Core" (cross-platform, now simply called ".NET").
This is why you might see several "Microsoft.NET Desktop Runtime" entries in your "Add or Remove Programs" list. They do not conflict; they coexist. microsoftnet desktop runtime 80 x64 2021