Q: why not use the LinuxBoot kernel directly?

[orangecms]

• final OS kernel is the more feature rich one, which gets more frequent upgrades
• LinuxBoot kernel has a smaller subset of features, is typically not generic
• some appliances do use a single kernel that could be loaded directly (from U-Boot SPL etc), stored in a small flash part, but that is for cost reasons and rather the exception

see also https://groups.google.com/g/linuxboot/c/zAR2dyoE4P0