Thus in your opinion the advise to train to failure that we see so often isn't as optimal as training with 1-2 RIR? Assuming you train often and that you gauge RIRs accurately most of the time.
Training to failure once a while is fine, but it is simply not possible to train at a high frequency and go to failure regularly. I personally do not prefer to train to failure more than once every two weeks per muscle group.
I advise people that are new to the gym (between 6 months to 2 years of training) to go to failure frequently so that they may accurately gauge what 1 RIR feels like.