וַֽיַּעֲשׂוּ֙ אֶת־אַבְנֵ֣י הַשֹּׁ֔הַם וַיָּ֣שֶׂם אֹתָ֗ם עַ֚ל כִּתְפֹ֣ת הָאֵפֹ֔ד
And they wrought the onyx stones, And he (Betzalel according to Netziv here) put them on the shoulder-pieces of the ephod.
This seems like a split job. Multiple people were involved in making it. Why didn't they finish the job and setting it in its proper place? Why did only Betzalel do that?