Is the "teaching" requirement for a patent really weak in court? It seems to me most patents are obfuscated works of legalese and ought to be invalidated on tha

Is the "teaching" requirement for a patent really weak in court? It seems to me most patents are obfuscated works of legalese and ought to be invalidated on that basis, by a relatively clear reading of the law. Or is it too easy to pay some expert witness $1000 to come in and say "yeah, that's totally clear to me and I'm an expert, so nyah nyah nyah."