Eggs are a seasonal product.
Unless one is using massive climate control, egg production drops or stops from about Christmas to Easter (the timing of the festivals are in part based on egg production) in the northern hemisphere.
How they get around this in canada, and I suspect most other places, is to store the eggs. In the grocery store here, a mass "manufactured " egg can be upto a year old before it gets to the grocery store.
Add to that the pressures of bird flu,
feed supply issues, etc... the news here has been warning of the upcoming egg shortage for weeks. I wouldn't doubt it would be worse somewhere without a marketing bord controlling supply and price.
Global issues have a huge impact on what we see in the grocery store.
The cure, be kind to your
local farmer.