Ok, see....I disagree.
Ethnic pride is not idiotic. Ethnic pride at the expense of/over all others IS idiotic.
Just like patriotism is not idiotic. But nationalism/exceptionalism at the expense of all others is idiotic.
Hell, it's one of the things I love about travelling: experiencing the pride of other people in who they are, where they come from, their culture and their ways. It's a sense of identity and self, tied to land and community, and it's a good thing. When it is part of you knowing how to appreciate ALL cultures and people in their own way - "hey, I'm a proud Texan, and like to show off football and bbq to visitors, and you're a proud German, and like to show off beer and wurst to visitors, we should party!" - it's a good thing. When it leans into tribalism and subjugation/attacks on other cultures, it's a huge fucking negative.
Obviously, culturally, we're leaning in HARD on the "negative tribal bullshit" angle these days. So I hear you. But man, I love going to a Greek festival, a Polish festival, a Turkish festival, a pachanga, Chinese new year, all that shit. It's cool to see people celebrating who they are. And they enjoy sharing it with others. That's the best of humanity. That we often turn into the worst of humanity.