That might be true for narrow-spectrum antibiotics, but broad-spectrum antibiotics target fundamental features that evolved very early so they're universal in b

That might be true for narrow-spectrum antibiotics, but broad-spectrum antibiotics target fundamental features that evolved very early so they're universal in bacteria, eg. beta-lactams such as penicillin target the enzymes that bacteria use to make their cell walls. In this case resistance occurs by attacking the antibiotic itself, producing extra enzyme so there's some spare, or tweaking the enzyme so the antibiotic can't harm it. It would be a much bigger story if bacteria were found with a completely different method of cell wall construction.