The regimen isn't really the amount of weight involved. It's how often you do it, how many reps, etc. For example, I'm doing interval training - something like, say, 10 chest presses, 10 lateral pulls, 30 seconds of crunches, and repeat this cycle three times. Then go to the next cycle, which might be something like incline pushups, bicep curls, and squats, again 3x.
If I were to change to, say, 5 reps at maximum weight just one time(heavy strength train), that would be a change in regimen.
That’s not a lifting regimen. You don’t need crunches if you’re doing heavy squats or deadlifts. You don’t need bicep curls at all. And chest press must be balanced with barbell rows. As to how many reps, I only do 10 or more reps during warmup. From there on out it’s 5 reps per set or so, and at the end I do a few heavy singles at about 85-90% of PR.
That is a lifting regimen; it's just not your lifting regimen. While mine has generally been more like what you're talking about, there's nothing wrong with people doing that kind of interval training.
Curls and crunches often give normal people better aesthetics than they had before. Some people want a 4/5/6 bench/squat/dead, other people want to look slightly better at the beach without utterly killing themselves in the gym. I know a couple order of magnitude more people with good aesthetics who control their diet and do a relatively candy-ass workout vs those rare powerlifting dudes who never do any ab work yet have abs visible through their squat suits.
I'm doing barbell rows as well. I typically do four sets of three different exercises each (plus warmup and cooldown), so I'll do 12 different exercises over the course of a workout, and what those 12 are vary somewhat week to week. It's typically about 2/3 weights, 1/3 bodyweight exercises.
It's lifting, it's a regimen, so it's a lifting regimen. And it's been very effective at quickly adding strength, endurance, and flexibility to my initially bad starting position.
Don't assume your way of doing things is the only way to do things.
If I were to change to, say, 5 reps at maximum weight just one time(heavy strength train), that would be a change in regimen.