I am currently doing free osu intro to permaculture course and perennials are much preferred over annuals in permaculture as there's less soil erosion and less overhead and less work!
There is a litany of problems with annuals.
The need to constantly replant every year
Leading to soil erosion.
Need for herbicides to control weeds.
Continual harvesting results in depleted soil.
Requiring fertilizer.
Short roots means low drought tolerance
Need for irrigation.
irrigation --> salinization
I like the first principles approach it takes.