They don't read bills. Their staff reads the bills and then makes sure that it conforms to the whims of their lobbyists. Then the staffers tell the representatives how to vote. This is literally how it happens 95% of the time. The other 5% are weirdos who actually either read the bill and make a speech about it, or they work with others against the bill and they help write the speech. This is why only the same handful of maga republicans (or crazy libs) actually stand up and give a speech about the bills. And we watch them and go...well what are the other 425 other reps (edit: /senators) doing, sittin on their hands?