It seems like a pretty normal local maximum situation, no? It's a solution which works "well enough" and means all light bulbs work in all light fixtures and all light fixtures work with all light bulbs. It would be better if we all moved away from LED, got all new standardized 24V light fixtures and stopped putting the power supply in the base of a standard E26 light bulb socket, but those kinds of transitions are costly.

It probably also doesn't help that this would require industry-wide cooperation between companies which would much rather sell their own light fixture + LED combo which people have to replace regularly than a light fixture which people buy once and keep for life.