House of the Dragon could have looked very different from the one that aired on HBO if author and co-creator George R.R. Martin had the last say. He wanted to start the show 40 years earlier than the opening scene which would have had even more time skips.
Where to Start the Pilot of House of the Dragon
“One of the big issues with all of these writers was where to begin,” Martin said. “[‘House of the Dragon’ showrunner Ryan Condal] began in [Episode 1] with the Great Council where the Lords vote that Jaehaerys’s heir — he’s just lost his son Baelon, who has died of appendicitis — so who is his heir now? And the lords vote to choose Viserys over Rhaenys.”
“We — myself and the other writers — had a lot of spirited discussions about where to begin that story,” Martin added.

One of the writers of the show wanted to start the story with the death of Viserys’s first wife Aemma (which was shown later in the show) while another wanted to start with the death of Viserys. That takes place near the end of the show and would have led to a whole different show if that was chosen as the starting point.
George R.R. Martin Wanted to Start the Show Much Earlier
Martin himself wanted to start much earlier and focus more on the first king Jaehaerys and his two sons.
“I would have began it like 40 years earlier with the episode I would have called ‘The Heir and the Spare,’ in which Jaehaerys’s two sons, Aemon and Baelon, are alive,” Martin said. “And we see the friendship, but also the rivalry, between the two sides of the great house. You know, Aemon dies accidentally when a Myrish crossbowman shoots him by accident on Tarth and then Jaehaerys has to decide who becomes the new heir. Is it the daughter of the older son who’s just died or is it the second son, who has sons of his own and is a man and she’s just a teenage girl?”
“You would have had 40 more years and you would have had even more time jumps and you would have even more re-castings and, yeah, I was the only one who was really enthused about that.
What Could Have Been
Not choosing to start 40 years earlier was the right call as it would have taken even longer to arrive to the epic Dance of the Dragons part. The acting made the show what it is and taking time away from those scenes would have hurt the show. Also, the time skips created aging issues as some characters aged whereas others looked to be immortal.
We will never know what could have been but the choices Martin and the other writers made seems like it the right one as most people enjoyed the first season.