Humans are herd beings. We have survived so far and have been able to reach the top of the hierarchy because of this behavior. Yes. But when you speak about categorization, we can see that in two. twitter.com/chumma_oru_acct/status/1603134539592712192
There are a few categories/groups that we can choose to be part of, and choose not to be part of. Like, dog vs cat, a supporter of a movement, etc. You can always choose one group and move out if you don't like them anymore.
But the other categorization is forced upon you. Your ethnicity, caste, and region of birth. You have no control over choosing this. This puts you in a position, where, even though you don't like to be part of this, you are still in that category.
Now, coming to your point of how putting a country flag is different from putting a caste identity. I don't agree with being proud of anything that came to you as an accident. Being born in a country, in a family of privilege or not is an accident.
But for this point, let us take a general opinion about having a country name in the bio.
A status of a country (economic/social) has the ability to vary. You can compare two different countries, and argue one is better than the other in various aspects.
You can argue the US is better than India, in terms of economics, and also, India is better than the US, in terms of obesity ratio. The same goes for states within India. The same goes for religion. (Note that you can always change your religion in this country)
Bt caste is a completely different categorization. Even though it is assigned to you by birth, there is already a pre-defined hierarchy structure among the group of caste. There isn't any way for one to change their caste or to change the social status of the caste they belong to
There is no way a brahmin is going to be socially oppressed just because of their caste. Or Dalit people will immediately go up in that triangle. Mind that I am mentioning the social status of the group and not the economic status overall.
There is one particular example which always helps us understand this. ஒரு தெரு ல 50 வீடு இருக்கு வச்சுப்போம். எல்லாரும் குடும்பமா வசிக்குறாங்க. இதுல ஒரு வீட்டு காரன் மட்டும், 'இது நல்லவர்கள் வாழும் வீடு' னு போட்டுகிறான் வச்சுப்போம்.
அப்போ மத்த வீட்டுல இருக்கறவங்க கெட்டவங்கனு ஆயிடுதுல. But எல்லாரும் அப்படி போட்டுக்கலாமேனு கேள்வி வரும். ஆனா firstu ஒருத்தன் எழுதினான்ல? அவன் எதுக்காக அவனை பெருசா காட்டிக்க நெனச்சான்னு யோசிச்சோம்னா இது விளங்கிடும்.
It is ok to do critical thinking with all the facts from science and evolution. But it is not going to help if you are neglecting the social factors too. Ignorance of our own privilege is the starting point of ignoring social oppression and imbalances.