I disagree, the reason why he made Rhaenyra heir was because he thought he couldn’t produce a son and because he wanted to ensure that Daemon was not his heir…. If anything I think keeping Rhaenyra heir once his eldest son was born made him look weak in the eyes of many lords (in those societies prejudices like this was the reality)… I think that the lords actually assumed that he would make Aegon his heir once he was born because thats what he was expected to do.

The reason why Aegon was so lazy was because he was given no priorities or responsibilities growing up as someone of his statue would usually have, if Viserys had raised him as the heir he would not be the same Aegon we hear about in F&B who is a drunk and who whores majority of the time. In all reality Viserys is a huge part of the reason his sons turned out the way they did. If Viserys sons turned out like Daemon and he didn’t like it well then thats on Viserys, instead of acting like he was a father of 5 he acted like he was a father of 1, aka his golden girl Rhaenyra. If he wanted his oldest sons to be better men then he should’ve stepped up as a father and taught them better instead of putting all his eggs in one basket.