Why does the Silo require an oppressive, class based society to maintain order?

Im rewatching season 1 again and the scenes depicting the differences between the levels’ standard of living made me wonder, wouldn’t the silo have more order if there were class equality?

Since the silo is a closed system (ie no other resources except for the ones present) it should be a truly equals’ society. Everyone is important, everyone does something that fits in the chain of command. Even the lowest of the levels play an important role in recycling things so the Silo is functional.

Yet, in the Order’s handbook it suggests that in order to contain a rebellion the upper levels must blame an uprising on Mechanical.

If Mechanical were fairly treated, that wouldn’t be a problem right?