Because conglomerates (ex. Tyson Foods) were upping their prices as shown by gross margins of 10% increasing to 15% [1].
> but it took another year or so before the consumers of that food started complaining about how much grocery stores were charging. Things happen very slowly.
Uh. More like immediately people complained; just throw a max date on a web search [2] and you'll find them readily.
I can't speak to your own personal anecdotes. But the price of eggs has been talked about ad nauseam since start of covid.
[2]: https://www.google.com/search?q=rising+food+prices&tbs=cdr%3...
[1]: https://www.macrotrends.net/stocks/charts/TSN/tyson-foods/gr...