I have a hypothesis that the best cloisonné beads were produced c1960s-70s by the older artists, who then retired in the early 80s once mass production got ramped up following Deng Xiaoping's 1978 economic "Reform and Opening Up." Newer cloisonné artisans were simply drafted from wherever without much regard to actual artistic talent.

These being the years surrounding the Cultural Revolution probably didn't help - the Beijing Enamel Factory was directed by Mao to cease producing traditional dragons and phoenixes and move instead to themes about peasants and Chinese opera. By the early 70s, because Cultural Revolution themes obviously were not selling well to the export market in HongKong and the Friendship Shops, and sales of traditional arts & crafts were important sources of foreign exchange, the screws seem to have come off. Nonetheless, cloisonné designs seem to play it safe with strictly floral motifs, and that includes beads. Not even after Mao and Zhou Enlai died in 1976 was there a much of a return to the neat things that were made in earlier years (with the exception of dragons, because everyone loves dragons) and execution was much sloppier.

I also suspect that a telltale marker between 60s/70s beads and 80s beads is the style of cloud spiral in the background. By the 80s, it's all JingFa-style clouds.

I used the phoenixes in a necklace the seller related was purchased in China in the 1970s to illustrate this - one artist is familiar with the traditional iconography, another is not, and has difficulty fitting the elaborate bird onto the bead.

Your two dragons seem also to illustrate this - the eyes of the dragon on the left are not distinguished, but are filled with red enamel the same as its whiskers. Careless! The dragon on the right is much better - someone knew what they were trying to achieve.