I've seen similar for pushups - do twice as many pushups as your 1x goal, in whatever reps/set is comfortable, slowly shifting to more reps/fewer sets until you are doing 2 sets of 100 pushups or whatever your goal is.
It's good to hear that there are gym trainers who advocate for this. From what I've seen, this approach seems to go contrary to popular belief and some people tend to be quite adamant about it, insisting on specific routines, splits, and rest days, but it's how I went from not being able to do a single push-up to effortlessly doing 10 consecutive one-arm push-ups. I just practice.