“A Dragon is no slave”-Daernerys Targaryen to a slave master

Daenerys then proceeds to lock Viserion and Rhageal up for an extended period of time in order to punish them for the misdeeds of their bother (this is a scare tactic used by slave masters used to intimidate). Viserion and Rhaegal were also of no use to Dracarys Dany at the time so she isolated them from the outside world, stunting their growth and depriving them of freedom and sunlight. 

Viserion and Rhaegal has showed no propensity for violence unlike Drogon. She could have let them go and grow by themselves and come back to her when and if they were ever ready. They’re two of the last three dragons on the planet so they shouldn’t be tied down as weapons.

Drogon went off on his own for like a year and he eventually came back by choice. Dragons are incredibly intelligent and have a form of wants and fears. I’m not saying that Daenerys was a master to Drogon, because she was his RIDER and MOTHER. Viserion and Rhaegal didn’t have that bond with her. Drogon was the obvious favorite so it makes sense that they wouldn’t want to stay with Dany.

If Rhaegal and Viserion has been set free they’d most likely still be alive. It’s Dany’s pursuit of the throne that killed them. And finally, season 8 proved that Dany didn’t even NEED the other two dragons to take King’s Landing. She only needed Drogon.

Daenerys uses her dragons only when it is convenient for her and Forest them to be WMDS. The Dragons are almost like the Unsullied in a way, they no nothing else, are taken as young children and forced to commit violence that they have become desensitized. 

Most of these are my ideas, but some of them are shared by many. Its a little incoherent but I wanted to share it.