I actually agree with hi “not training toi failure” point. I don’t agree with the “no explosive” work. But Scott comes from a bodybuilding background, and while he did start to include some explosive work later in his career that is not his speciality.
I know from experience that people who maintain or even improve speed and power as they get older age a lot better (a friend of mine is still competing in olympic lifting at 83, clean & jerking 185lbs).
But of course for someone who has never moved explosively in his live it might be hazardous to start training with explosive exercises past 50 because the body is not prepared for it. So it has to be phased in gradually,