Rickettsial still gets destroyed by normal tetracyclines.
Brucellosis is treated by rifampicin not a tretracycline. Any superbugs,, and yes there are some, are the fault of something else than farming. Is your information super dated?
spirochetal infections have the preferred treatments of doxycycline yes but also there are alternatives like colistin, penicillin, or ceftriaxone.
Good ol' chlamydia, on the decline now for two years, no superbugs yet but it's being watched.
The whole conversation is not to lose our shit over farm animal antibiotics, it's not the problem.