It's all just bro science.
They're abusing so much that they wouldn't even be able to tell what's happening. They don't even give the compounds enough time to build. These are the same guys claiming that things like weak ass junk such as Anavar is what makes all the difference to their cut when added etc, but they forego to mention they are also on Tren and HGH and Test and Insulin etc. I can guarantee you they wouldn't know what the hell they are doing, with each compound and what it is responsible for. I mean it is certainly not some female androgen replacement drug like Anavar at the tail end that makes you look that way, it's the grams of other shit you were running before that.
There's only two things that are gonna stop you: myostatin or androgen resistance. Both are very real, yet both are in no way what these guys are claiming or experiencing.
If it were true, we would all eventually become women because our androgens like Test and DHT would just "stop working" after 6 weeks of our lives.
Your Androgen Receptors get down-regulated over time, but nowhere near to the point that 4 - 6 weeks of gear will stop them from working. Just that most of these guys are so used to abusing 700+ grams of Tren etc, that they 'feel' like they aren't getting any benefit from them.
You can become somewhat acclimatized to anything, but not in this way. And certainly not swapping to another compound would 'solve' the issue being another androgen steroid hormone. It's sort of like saying "I'm sick of wearing a dark blue shirt, so I'll wear a light blue one. There we go, different colour!" No, they are still blue shirts.