Why does caste become so relevant all sudden, when it comes to marriage?

I don't wanna go through this, everyday it is getting more difficult. As if like all boils down to the caste than who I am, how I am as an individual no one even considering that in family, search are limited to caste. I feel like I should just run away somewhere. I am not ready for this new drama. Am I just overthinking. Any words from your experience will help a lot.