Sure, I personally use this all the time. I’v never thought of it as strength to hypertrophy though. I have always just viewed it as, for example, “I’m taking a weight I did for 3x3, and now I can do it for 3x8. Therefore I am stronger.” If that makes any sense.
Thibaudeau has written about double progression here (increasing reps and then increasing weight), and some variations in other articles. Dan John has also talked about it, in the context of “owning” a weight before going heavier.
It was also one of the first popular systems back in the 1930s and '40s, for example doing sets of 10 and working up with the same weight for sets of 20.
I don’t remember what article it was, as I’ve read so much from him, but I remember him talking about how, at least on most of the heavy compound movements, he preferred to just use the 25 and 45 lbs plates, which is something I mostly adhere to as well. I don’t like taking micro-jumps from week to week. I think that’s tedious. If your max bench is 295, keep working at 225 and 275 until you can handle 315. That’s sort of the theory behind it, and honestly, I think it makes a ton of sense.
This is how I got my first ever 225 squat lol. Took a leap from 185 to 225. I think it works better if you are Already somewhat strong. I remember in the article he had guys jump weights in the snatch from 95 to 135 to 185, which seems pretty crazy to me. But if you have no other weights to work with I think your body can for sure adapt.
Doug Hepburn and Anthony Ditillo are two “Old School” guys who used this sort of progression style.
It definetly works. Two possible “issues/problems” that could come up;
-Boredom. Sometimes lifting the same weight over and over, for almost the same reps can get boring. This doesn’t necesarily apply to everyone, of course.
-Going too heavy the first time. Because 3 x3 is so “easy” you might push the weights a little that first workout. It feels OK, but in 2-3 workouts you are nearly killing yourself for 3 sets. If you stick to 85%, this shouldn’t be a problem.
It’s not really about not having any other weights to work with. It works because reps build strength more effectively than maximal loads. People really underestimate how much strength you can build mostly working in the 5-12 rep range. Heavy singles, doubles, and triples absolutely have their place in training, but they are more for becoming acclimated to lifting loads that are close to a max, so that the nervous system can handle that in competition. But those reps don’t build the strength base nearly as effectively as higher reps. I personally believe that sets of 10 on the squat are the absolute best way to build it. If you did 5 sets of 10 squats forever and ever, and ate well, you could become incredibly strong. Lower reps just aren’t necessary. The ONLY exception to this rule in my own training is deadlift, because higher reps are SO taxing on the body, that injury risk becomes to high for my own taste. I simply can’t hit multiple sets of 8+ on the deadlift every week and expect to live through it, lol.