good crops, prosperity, 10**28
穣 centers on abundant harvests and the resulting prosperity. The large-number sense (10^28) is a specialized extension of that idea of overflowing plenty.
穣 combines 禾 (grain plant) with 㐮, which likely contributes the sound and the idea of fullness or abundance, together suggesting a rich harvest.
The grain plant 禾 beside the full-looking 㐮 suggests a field overflowing with ripe crops. Picture a farmer surrounded by good crops and prosperity.
For ジョウ, imagine a joyful farmer named Joe surveying his abundant harvest: Joe -> ジョウ, and his fields are full of good crops.