Mixing rep ranges in the same session

I heard that mixing mixing rep ranges in the same session is bad and that’s why things like dup or concurrent periodisation are so popular because you can work in different rep ranges or different training modalities on different days. Is there any truth to this?

What? Why would it be “bad”?

Bad was a poor word choice, it’s not bad and it’s not you can’t get jacked and strong doing it it’s that it limits the amount of workload that can be done making it inferior to a concurrent periodisation style in which you would have entire training sessions focused on the different performance elements however you seem to disagree with that. For example if you hit a heavy triple on bench that will fatigue you a lot making any back off work a lot lighter than if you did stuff focused on a different performance element on a different day like how concurrent periodisation had you do. That’s just what I’ve heard though

it’s that it limits the amount of workload that can be done making it inferior to a concurrent periodisation style in which you would have entire training sessions focused on the different performance elements

Why would this be the case?

For example if you hit a heavy triple on bench that will fatigue you a lot making any back off work a lot lighter than if you did stuff focused on a different performance element on a different day like how concurrent periodisation had you do

One heavy triple on bench shouldn’t fatigue you that much.