Apple may not design for repairability, but what you are saying is not true. I have personally purchased and installed genuine replacement displays on MacBooks with no involvement from Apple.

Apple publishes repair guides for this (e.g., https://support.apple.com/en-us/120768) as does iFixit. Genuine parts are available for purchase and tools are available to rent by individuals (see https://support.apple.com/self-service-repair, which specifically mentions display replacement). Skill and patience are required; replacement by Apple is not.