I’d say that at least for Americans, yes, there is a cultural expectation among many groups to eat meat at every meal, and for meat to be the predominant aspect of the meal. A lot of that is regional or generational though, and it’s starting to change.

What other people have said is pertinent though. A lot of eastern countries are tropical, so their habits can’t always be applied to temperate or cold climates. It’s very easy to center your eating habits around fresh produce and rice when you live in a place where those things can be grown year round and are essentially falling off of trees for free. Historically, people in cold climates (including eastern countries) eat a lot more meat, or even base their diet around meat. Even today with modern conveniences, a lot of people in parts of Alaska and Canada just don’t eat fresh vegetables as a daily thing because they can’t grow there and shipping them, even frozen vegetables, there makes them an extremely pricey luxury. And the people living there have been living on meat and fish for as long as they’ve been there. While the idea that people in temperate areas are somehow entitled to meat on a thrice-daily basis is obviously ridiculous and overprivileged, so too is it a privilege to live someplace where eating fresh plant based dishes for every meal is cheap and easy, and to assume everyone has the same access to those things.