Meat wasn't a staple food 100 years ago, it was too expensive for regular people. Same with milk, if you didn't own a cow, you just didn't drink it. You drank some sort of ale.
My grandfather was a kid at the end of the Great Depression. One of the stories which blew my mind growing up was that he ate beef basically twice a year, when his cousins on a small dairy farm culled the herd.
His mother kept chickens, so they had eggs - to the point that as an adult he never eats them because he got sick of them by the time he graduated from high school.
Yep, (western) people are acting like meat is a human right and a staple day to day food.
My grandparents were the first generation in my country who started to have regular access to meat after WW2. Before that it was either a rare thing and much of the "meat" they ate was offal.
Pea soup was 99% peas and a small chunk of smoked meat added for flavour.
Meanwhile billions of people live perfectly normal lives eating legumes (beans, chickpeas, peanuts) for protein.
I think some people misconstrue traditional with today's sensationalized Food TV marketing. Which tradition are we even talking about? The world has never had this much access to food. We eat like almost every culture's royal family every night of the week, and pretend like it always been this way.
His mother kept chickens, so they had eggs - to the point that as an adult he never eats them because he got sick of them by the time he graduated from high school.