Is favoritism considered discrimination and can I record it?

My job is littered with favoritism. Like the older managers favor the “young” and fit employees more.It’s kind of ick

Today an employee( a young one) literally told me that they “barely have to do any work”

(While they literally work me like a dog)

I’m in my 30s and have some health issues

Can I record that statement by voice recording or even video recording(phone hidden?)

And use that as solid proof/evidence?

I live in Texas BTW

I’m not trying to get the employee in trouble btw just going after the corrupt management